Systems and methods for cross-application authoring, transfer, and evaluation of rigging control systems for virtual characters

ABSTRACT

Various examples of cross-application systems and methods for authoring, transferring, and evaluating rigging control systems for virtual characters are disclosed. A first application, which implements a first rigging control protocol, can provide an input associated with a request for a behavior from the rig for the virtual character. The input can be converted to be compatible with a second rigging control protocol that is different from the first rigging control protocol. One or more control systems can be evaluated based on the input to determine an output to provide the requested behavior from the virtual character rig. The one or more control systems can be defined according to the second rigging control protocol. The output can be converted to be compatible with the first rigging control protocol and provided to the first application to manipulate the virtual character according to the requested behavior.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/047,339, filed Oct. 13, 2020, and entitled “SYSTEMS AND METHODS FORCROSS-APPLICATION AUTHORING, TRANSFER, AND EVALUATION OF RIGGING CONTROLSYSTEMS FOR VIRTUAL CHARACTERS,” which is a national phase of PCT PatentApplication PCT/US2019/027350, filed Apr. 12, 2019, and entitled“SYSTEMS AND METHODS FOR CROSS-APPLICATION AUTHORING, TRANSFER, ANDEVALUATION OF RIGGING CONTROL SYSTEMS FOR VIRTUAL CHARACTERS,” whichclaims priority to U.S. Provisional Patent Application No. 62/658,415,filed Apr. 16, 2018, and entitled “SYSTEMS AND METHODS FORCROSS-APPLICATION AUTHORING, TRANSFER, AND EVALUATION OF RIGGING CONTROLSYSTEMS FOR VIRTUAL CHARACTERS.” Any and all applications for which aforeign or domestic priority claim is identified above and/or in theApplication Data Sheet as filed with the present application are herebyincorporated by reference under 37 CFR 1.57.

FIELD

The present disclosure relates to virtual reality and augmented reality,including mixed reality, imaging and visualization systems, and moreparticularly to tools for efficiently enabling cross-applicationconfigurations of virtual characters.

BACKGROUND

Modern computing and display technologies have facilitated thedevelopment of systems for so called “virtual reality,” “augmentedreality,” and “mixed reality” experiences, wherein digitally reproducedimages are presented to a user in a manner such that they seem to be, ormay be perceived as, real. A virtual reality (VR) scenario typicallyinvolves presentation of computer-generated virtual image informationwithout transparency to other actual real-world visual input. Anaugmented reality (AR) scenario typically involves presentation ofvirtual image information as an augmentation to visualization of theactual world around the user. Mixed reality (MR) is a type of augmentedreality in which physical and virtual objects may co-exist and interactin real time. Systems and methods disclosed herein address variouschallenges related to VR, AR and MR technology.

SUMMARY

In some embodiments, a method for executing a rig for a virtualcharacter comprises: receiving, from a first application whichimplements a first rigging control protocol, an input associated with arequest for a behavior from the rig for the virtual character;converting the input to be compatible with a second rigging controlprotocol that is different from the first rigging control protocol;evaluating one or more control systems, based on the input, to determinean output to provide the requested behavior from the virtual characterrig, the one or more control systems being defined according to thesecond rigging control protocol; converting the output to be compatiblewith the first rigging control protocol; and providing the output to thefirst application to manipulate the virtual character according to therequested behavior.

In some embodiments, a method for transferring a rigging control systemfor a virtual character comprises: creating, in a first applicationwhich implements a first rigging control protocol, a rigging controlsystem description, the rigging control system description being definedaccording to a different second rigging control protocol and specifyinga rigging control input and a rule for operating on the rigging controlinput to produce a rigging control output; writing the rigging controlsystem description to a data file; and initiating transfer of the datafile to a second application.

BRIEF DESCRIPTION OF THE DRAWINGS

Details of one or more implementations of the subject matter describedin this specification are set forth in the accompanying drawings and thedescription below. Other features, aspects, and advantages will becomeapparent from the description, the drawings, and the claims.

FIG. 1 depicts an illustration of a mixed reality scenario with certainvirtual reality objects, and certain physical objects viewed by aperson.

FIG. 2 schematically illustrates an example of a wearable system.

FIG. 3 schematically illustrates example components of a wearablesystem.

FIG. 4 schematically illustrates an example of a waveguide stack of awearable device for outputting image information to a user.

FIG. 5 is a process flow diagram of an example of a method forinteracting with a virtual user interface.

FIG. 6A is a block diagram of another example of a wearable system whichcan comprise an avatar processing and rendering system.

FIG. 6B illustrates example components of an avatar processing andrendering system.

FIG. 7 is a block diagram of an example of a wearable system includingvarious inputs into the wearable system.

FIG. 8 is a process flow diagram of an example of a method of renderingvirtual content in relation to recognized objects.

FIG. 9A schematically illustrates an overall system view depictingmultiple wearable systems interacting with each other.

FIG. 9B illustrates an example telepresence session.

FIG. 10 illustrates an example of an avatar as perceived by a user of awearable system.

FIG. 11 illustrates an example computing environment forcross-application implementations of rigging control systems.

FIG. 12 illustrates an example of an embedded framework that can be usedfor cross-application authoring, transfer, and evaluation of riggingcontrol systems for a virtual character.

FIG. 13 illustrates an example flow diagram for cross-applicationtransfer of rigging control systems.

FIGS. 14A-14C illustrate example processes for cross-applicationauthoring, transfer, and evaluation of rigging control systems.

Throughout the drawings, reference numbers may be re-used to indicatecorrespondence between referenced elements. The drawings are provided toillustrate example embodiments described herein and are not intended tolimit the scope of the disclosure.

DETAILED DESCRIPTION Overview

A virtual avatar may be a virtual representation of a real or fictionalperson (or creature or personified object) in an AR/VR/MR environment.For example, during a telepresence session in which two AR/VR/MR usersare interacting with each other, a viewer can perceive an avatar ofanother user in the viewer's environment and thereby create a tangiblesense of the other user's presence in the viewer's environment. Theavatar can also provide a way for users to interact with each other anddo things together in a shared virtual environment. For example, astudent attending an online class can perceive and interact with avatarsof other students or the teacher in a virtual classroom. As anotherexample, a user playing a game in an AR/VR/MR environment may view andinteract with avatars of other players in the game.

Embodiments of the disclosed systems and methods may provide forimproved avatars and a more realistic interaction between a user of thewearable system and avatars in the user's environment. Although theexamples in this disclosure describe animating a human-shaped avatar,similar techniques can also be applied to animals, fictitious creatures,objects, etc.

Examples of 3D Display of a Wearable System

A wearable system (also referred to herein as an augmented reality (AR)system) can be configured to present 2D or 3D virtual images to a user.The images may be still images, frames of a video, or a video, incombination or the like. At least a portion of the wearable system canbe implemented on a wearable device that can present a VR, AR, or MRenvironment, alone or in combination, for user interaction. The wearabledevice can be used interchangeably as an AR device (ARD). Further, forthe purpose of the present disclosure, the term “AR” is usedinterchangeably with the term “MR”.

FIG. 1 depicts an illustration of a mixed reality scenario with certainvirtual reality objects, and certain physical objects viewed by aperson. In FIG. 1, an MR scene 100 is depicted wherein a user of an MRtechnology sees a real-world park-like setting 110 featuring people,trees, buildings in the background, and a concrete platform 120. Inaddition to these items, the user of the MR technology also perceivesthat he “sees” a robot statue 130 standing upon the real-world platform120, and a cartoon-like avatar character 140 flying by which seems to bea personification of a bumble bee, even though these elements do notexist in the real world.

In order for the 3D display to produce a true sensation of depth, andmore specifically, a simulated sensation of surface depth, it may bedesirable for each point in the display's visual field to generate anaccommodative response corresponding to its virtual depth. If theaccommodative response to a display point does not correspond to thevirtual depth of that point, as determined by the binocular depth cuesof convergence and stereopsis, the human eye may experience anaccommodation conflict, resulting in unstable imaging, harmful eyestrain, headaches, and, in the absence of accommodation information,almost a complete lack of surface depth.

VR, AR, and MR experiences can be provided by display systems havingdisplays in which images corresponding to a plurality of depth planesare provided to a viewer. The images may be different for each depthplane (e.g., provide slightly different presentations of a scene orobject) and may be separately focused by the viewer's eyes, therebyhelping to provide the user with depth cues based on the accommodationof the eye required to bring into focus different image features for thescene located on different depth plane or based on observing differentimage features on different depth planes being out of focus. Asdiscussed elsewhere herein, such depth cues provide credible perceptionsof depth.

FIG. 2 illustrates an example of wearable system 200 which can beconfigured to provide an AR/VR/MR scene. The wearable system 200 canalso be referred to as the AR system 200. The wearable system 200includes a display 220, and various mechanical and electronic modulesand systems to support the functioning of display 220. The display 220may be coupled to a frame 230, which is wearable by a user, wearer, orviewer 210. The display 220 can be positioned in front of the eyes ofthe user 210. The display 220 can present AR/VR/MR content to a user.The display 220 can comprise a head mounted display (HMD) that is wornon the head of the user.

In some embodiments, a speaker 240 is coupled to the frame 230 andpositioned adjacent the ear canal of the user (in some embodiments,another speaker, not shown, is positioned adjacent the other ear canalof the user to provide for stereo/shapeable sound control). The display220 can include an audio sensor (e.g., a microphone) 232 for detectingan audio stream from the environment and capture ambient sound. In someembodiments, one or more other audio sensors, not shown, are positionedto provide stereo sound reception. Stereo sound reception can be used todetermine the location of a sound source. The wearable system 200 canperform voice or speech recognition on the audio stream.

The wearable system 200 can include an outward-facing imaging system 464(shown in FIG. 4) which observes the world in the environment around theuser. The wearable system 200 can also include an inward-facing imagingsystem 462 (shown in FIG. 4) which can track the eye movements of theuser. The inward-facing imaging system may track either one eye'smovements or both eyes' movements. The inward-facing imaging system 462may be attached to the frame 230 and may be in electrical communicationwith the processing modules 260 or 270, which may process imageinformation acquired by the inward-facing imaging system to determine,e.g., the pupil diameters or orientations of the eyes, eye movements oreye pose of the user 210. The inward-facing imaging system 462 mayinclude one or more cameras. For example, at least one camera may beused to image each eye. The images acquired by the cameras may be usedto determine pupil size or eye pose for each eye separately, therebyallowing presentation of image information to each eye to be dynamicallytailored to that eye.

As an example, the wearable system 200 can use the outward-facingimaging system 464 or the inward-facing imaging system 462 to acquireimages of a pose of the user. The images may be still images, frames ofa video, or a video.

The display 220 can be operatively coupled 250, such as by a wired leador wireless connectivity, to a local data processing module 260 whichmay be mounted in a variety of configurations, such as fixedly attachedto the frame 230, fixedly attached to a helmet or hat worn by the user,embedded in headphones, or otherwise removably attached to the user 210(e.g., in a backpack-style configuration, in a belt-coupling styleconfiguration).

The local processing and data module 260 may comprise a hardwareprocessor, as well as digital memory, such as non-volatile memory (e.g.,flash memory), both of which may be utilized to assist in theprocessing, caching, and storage of data. The data may include data a)captured from sensors (which may be, e.g., operatively coupled to theframe 230 or otherwise attached to the user 210), such as image capturedevices (e.g., cameras in the inward-facing imaging system or theoutward-facing imaging system), audio sensors (e.g., microphones),inertial measurement units (IMUs), accelerometers, compasses, globalpositioning system (GPS) units, radio devices, or gyroscopes; or b)acquired or processed using remote processing module 270 or remote datarepository 280, possibly for passage to the display 220 after suchprocessing or retrieval. The local processing and data module 260 may beoperatively coupled by communication links 262 or 264, such as via wiredor wireless communication links, to the remote processing module 270 orremote data repository 280 such that these remote modules are availableas resources to the local processing and data module 260. In addition,remote processing module 280 and remote data repository 280 may beoperatively coupled to each other.

In some embodiments, the remote processing module 270 may comprise oneor more processors configured to analyze and process data or imageinformation. In some embodiments, the remote data repository 280 maycomprise a digital data storage facility, which may be available throughthe internet or other networking configuration in a “cloud” resourceconfiguration. In some embodiments, all data is stored and allcomputations are performed in the local processing and data module,allowing fully autonomous use from a remote module.

Example Components of A Wearable System

FIG. 3 schematically illustrates example components of a wearablesystem. FIG. 3 shows a wearable system 200 which can include a display220 and a frame 230. A blown-up view 202 schematically illustratesvarious components of the wearable system 200. In certain implements,one or more of the components illustrated in FIG. 3 can be part of thedisplay 220. The various components alone or in combination can collecta variety of data (such as e.g., audio or visual data) associated withthe user of the wearable system 200 or the user's environment. It shouldbe appreciated that other embodiments may have additional or fewercomponents depending on the application for which the wearable system isused. Nevertheless, FIG. 3 provides a basic idea of some of the variouscomponents and types of data that may be collected, analyzed, and storedthrough the wearable system.

FIG. 3 shows an example wearable system 200 which can include thedisplay 220. The display 220 can comprise a display lens 226 that may bemounted to a user's head or a housing or frame 230, which corresponds tothe frame 230. The display lens 226 may comprise one or more transparentmirrors positioned by the housing 230 in front of the user's eyes 302,304 and may be configured to bounce projected light 338 into the eyes302, 304 and facilitate beam shaping, while also allowing fortransmission of at least some light from the local environment. Thewavefront of the projected light beam 338 may be bent or focused tocoincide with a desired focal distance of the projected light. Asillustrated, two wide-field-of-view machine vision cameras 316 (alsoreferred to as world cameras) can be coupled to the housing 230 to imagethe environment around the user. These cameras 316 can be dual capturevisible light/non-visible (e.g., infrared) light cameras. The cameras316 may be part of the outward-facing imaging system 464 shown in FIG.4. Image acquired by the world cameras 316 can be processed by the poseprocessor 336. For example, the pose processor 336 can implement one ormore object recognizers 708 (e.g., shown in FIG. 7) to identify a poseof a user or another person in the user's environment or to identify aphysical object in the user's environment.

With continued reference to FIG. 3, a pair of scanned-lasershaped-wavefront (e.g., for depth) light projector modules with displaymirrors and optics configured to project light 338 into the eyes 302,304 are shown. The depicted view also shows two miniature infraredcameras 324 paired with infrared light (such as light emitting diodes“LED”s), which are configured to be able to track the eyes 302, 304 ofthe user to support rendering and user input. The cameras 324 may bepart of the inward-facing imaging system 462 shown in FIG. 4 Thewearable system 200 can further feature a sensor assembly 339, which maycomprise X, Y, and Z axis accelerometer capability as well as a magneticcompass and X, Y, and Z axis gyro capability, preferably providing dataat a relatively high frequency, such as 200 Hz. The sensor assembly 339may be part of the IMU described with reference to FIG. 2A The depictedsystem 200 can also comprise a head pose processor 336, such as an ASIC(application specific integrated circuit), FPGA (field programmable gatearray), or ARM processor (advanced reduced-instruction-set machine),which may be configured to calculate real or near-real time user headpose from wide field of view image information output from the capturedevices 316. The head pose processor 336 can be a hardware processor andcan be implemented as part of the local processing and data module 260shown in FIG. 2A.

The wearable system can also include one or more depth sensors 234. Thedepth sensor 234 can be configured to measure the distance between anobject in an environment to a wearable device. The depth sensor 234 mayinclude a laser scanner (e.g., a lidar), an ultrasonic depth sensor, ora depth sensing camera. In certain implementations, where the cameras316 have depth sensing ability, the cameras 316 may also be consideredas depth sensors 234.

Also shown is a processor 332 configured to execute digital or analogprocessing to derive pose from the gyro, compass, or accelerometer datafrom the sensor assembly 339. The processor 332 may be part of the localprocessing and data module 260 shown in FIG. 2. The wearable system 200as shown in FIG. 3 can also include a position system such as, e.g., aGPS 337 (global positioning system) to assist with pose and positioninganalyses. In addition, the GPS may further provide remotely-based (e.g.,cloud-based) information about the user's environment. This informationmay be used for recognizing objects or information in user'senvironment.

The wearable system may combine data acquired by the GPS 337 and aremote computing system (such as, e.g., the remote processing module270, another user's ARD, etc.) which can provide more information aboutthe user's environment. As one example, the wearable system candetermine the user's location based on GPS data and retrieve a world map(e.g., by communicating with a remote processing module 270) includingvirtual objects associated with the user's location. As another example,the wearable system 200 can monitor the environment using the worldcameras 316 (which may be part of the outward-facing imaging system 464shown in FIG. 4). Based on the images acquired by the world cameras 316,the wearable system 200 can detect objects in the environment (e.g., byusing one or more object recognizers 708 shown in FIG. 7). The wearablesystem can further use data acquired by the GPS 337 to interpret thecharacters.

The wearable system 200 may also comprise a rendering engine 334 whichcan be configured to provide rendering information that is local to theuser to facilitate operation of the scanners and imaging into the eyesof the user, for the user's view of the world. The rendering engine 334may be implemented by a hardware processor (such as, e.g., a centralprocessing unit or a graphics processing unit). In some embodiments, therendering engine is part of the local processing and data module 260.The rendering engine 334 can be communicatively coupled (e.g., via wiredor wireless links) to other components of the wearable system 200. Forexample, the rendering engine 334, can be coupled to the eye cameras 324via communication link 274, and be coupled to a projecting subsystem 318(which can project light into user's eyes 302, 304 via a scanned laserarrangement in a manner similar to a retinal scanning display) via thecommunication link 272. The rendering engine 334 can also be incommunication with other processing units such as, e.g., the sensor poseprocessor 332 and the image pose processor 336 via links 276 and 294respectively.

The cameras 324 (e.g., mini infrared cameras) may be utilized to trackthe eye pose to support rendering and user input. Some example eye posesmay include where the user is looking or at what depth he or she isfocusing (which may be estimated with eye vergence). The GPS 337, gyros,compass, and accelerometers 339 may be utilized to provide coarse orfast pose estimates. One or more of the cameras 316 can acquire imagesand pose, which in conjunction with data from an associated cloudcomputing resource, may be utilized to map the local environment andshare user views with others.

The example components depicted in FIG. 3 are for illustration purposesonly. Multiple sensors and other functional modules are shown togetherfor ease of illustration and description. Some embodiments may includeonly one or a subset of these sensors or modules. Further, the locationsof these components are not limited to the positions depicted in FIG. 3.Some components may be mounted to or housed within other components,such as a belt-mounted component, a hand-held component, or a helmetcomponent. As one example, the image pose processor 336, sensor poseprocessor 332, and rendering engine 334 may be positioned in a beltpackand configured to communicate with other components of the wearablesystem via wireless communication, such as ultra-wideband, Wi-Fi,Bluetooth, etc., or via wired communication. The depicted housing 230preferably is head-mountable and wearable by the user. However, somecomponents of the wearable system 200 may be worn to other portions ofthe user's body. For example, the speaker 240 may be inserted into theears of a user to provide sound to the user.

Regarding the projection of light 338 into the eyes 302, 304 of theuser, in some embodiment, the cameras 324 may be utilized to measurewhere the centers of a user's eyes are geometrically verged to, which,in general, coincides with a position of focus, or “depth of focus”, ofthe eyes. A 3-dimensional surface of all points the eyes verge to can bereferred to as the “horopter”. The focal distance may take on a finitenumber of depths, or may be infinitely varying. Light projected from thevergence distance appears to be focused to the subject eye 302, 304,while light in front of or behind the vergence distance is blurred.Examples of wearable devices and other display systems of the presentdisclosure are also described in U.S. Patent Publication No.2016/0270656, which is incorporated by reference herein in its entirety.

The human visual system is complicated and providing a realisticperception of depth is challenging. Viewers of an object may perceivethe object as being three-dimensional due to a combination of vergenceand accommodation. Vergence movements (e.g., rolling movements of thepupils toward or away from each other to converge the lines of sight ofthe eyes to fixate upon an object) of the two eyes relative to eachother are closely associated with focusing (or “accommodation”) of thelenses of the eyes. Under normal conditions, changing the focus of thelenses of the eyes, or accommodating the eyes, to change focus from oneobject to another object at a different distance will automaticallycause a matching change in vergence to the same distance, under arelationship known as the “accommodation-vergence reflex.” Likewise, achange in vergence will trigger a matching change in accommodation,under normal conditions. Display systems that provide a better matchbetween accommodation and vergence may form more realistic andcomfortable simulations of three-dimensional imagery.

Further spatially coherent light with a beam diameter of less than about0.7 millimeters can be correctly resolved by the human eye regardless ofwhere the eye focuses. Thus, to create an illusion of proper focaldepth, the eye vergence may be tracked with the cameras 324, and therendering engine 334 and projection subsystem 318 may be utilized torender all objects on or close to the horopter in focus, and all otherobjects at varying degrees of defocus (e.g., using intentionally-createdblurring). Preferably, the system 220 renders to the user at a framerate of about 60 frames per second or greater. As described above,preferably, the cameras 324 may be utilized for eye tracking, andsoftware may be configured to pick up not only vergence geometry butalso focus location cues to serve as user inputs. Preferably, such adisplay system is configured with brightness and contrast suitable forday or night use.

In some embodiments, the display system preferably has latency of lessthan about 20 milliseconds for visual object alignment, less than about0.1 degree of angular alignment, and about 1 arc minute of resolution,which, without being limited by theory, is believed to be approximatelythe limit of the human eye. The display system 220 may be integratedwith a localization system, which may involve GPS elements, opticaltracking, compass, accelerometers, or other data sources, to assist withposition and pose determination; localization information may beutilized to facilitate accurate rendering in the user's view of thepertinent world (e.g., such information would facilitate the glasses toknow where they are with respect to the real world).

In some embodiments, the wearable system 200 is configured to displayone or more virtual images based on the accommodation of the user'seyes. Unlike prior 3D display approaches that force the user to focuswhere the images are being projected, in some embodiments, the wearablesystem is configured to automatically vary the focus of projectedvirtual content to allow for a more comfortable viewing of one or moreimages presented to the user. For example, if the user's eyes have acurrent focus of 1 m, the image may be projected to coincide with theuser's focus. If the user shifts focus to 3 m, the image is projected tocoincide with the new focus. Thus, rather than forcing the user to apredetermined focus, the wearable system 200 of some embodiments allowsthe user's eye to a function in a more natural manner.

Such a wearable system 200 may eliminate or reduce the incidences of eyestrain, headaches, and other physiological symptoms typically observedwith respect to virtual reality devices. To achieve this, variousembodiments of the wearable system 200 are configured to project virtualimages at varying focal distances, through one or more variable focuselements (VFEs). In one or more embodiments, 3D perception may beachieved through a multi-plane focus system that projects images atfixed focal planes away from the user. Other embodiments employ variableplane focus, wherein the focal plane is moved back and forth in thez-direction to coincide with the user's present state of focus.

In both the multi-plane focus systems and variable plane focus systems,wearable system 200 may employ eye tracking to determine a vergence ofthe user's eyes, determine the user's current focus, and project thevirtual image at the determined focus. In other embodiments, wearablesystem 200 comprises a light modulator that variably projects, through afiber scanner, or other light generating source, light beams of varyingfocus in a raster pattern across the retina. Thus, the ability of thedisplay of the wearable system 200 to project images at varying focaldistances not only eases accommodation for the user to view objects in3D, but may also be used to compensate for user ocular anomalies, asfurther described in U.S. Patent Publication No. 2016/0270656, which isincorporated by reference herein in its entirety. In some otherembodiments, a spatial light modulator may project the images to theuser through various optical components. For example, as describedfurther below, the spatial light modulator may project the images ontoone or more waveguides, which then transmit the images to the user.

Waveguide Stack Assembly

FIG. 4 illustrates an example of a waveguide stack for outputting imageinformation to a user. A wearable system 400 includes a stack ofwaveguides, or stacked waveguide assembly 480 that may be utilized toprovide three-dimensional perception to the eye/brain using a pluralityof waveguides 432 b, 434 b, 436 b, 438 b, 4400 b. In some embodiments,the wearable system 400 may correspond to wearable system 200 of FIG. 2,with FIG. 4 schematically showing some parts of that wearable system 200in greater detail. For example, in some embodiments, the waveguideassembly 480 may be integrated into the display 220 of FIG. 2.

With continued reference to FIG. 4, the waveguide assembly 480 may alsoinclude a plurality of features 458, 456, 454, 452 between thewaveguides. In some embodiments, the features 458, 456, 454, 452 may belenses. In other embodiments, the features 458, 456, 454, 452 may not belenses. Rather, they may simply be spacers (e.g., cladding layers orstructures for forming air gaps).

The waveguides 432 b, 434 b, 436 b, 438 b, 440 b or the plurality oflenses 458, 456, 454, 452 may be configured to send image information tothe eye with various levels of wavefront curvature or light raydivergence. Each waveguide level may be associated with a particulardepth plane and may be configured to output image informationcorresponding to that depth plane. Image injection devices 420, 422,424, 426, 428 may be utilized to inject image information into thewaveguides 440 b, 438 b, 436 b, 434 b, 432 b, each of which may beconfigured to distribute incoming light across each respectivewaveguide, for output toward the eye 410. Light exits an output surfaceof the image injection devices 420, 422, 424, 426, 428 and is injectedinto a corresponding input edge of the waveguides 440 b, 438 b, 436 b,434 b, 432 b. In some embodiments, a single beam of light (e.g., acollimated beam) may be injected into each waveguide to output an entirefield of cloned collimated beams that are directed toward the eye 410 atparticular angles (and amounts of divergence) corresponding to the depthplane associated with a particular waveguide.

In some embodiments, the image injection devices 420, 422, 424, 426, 428are discrete displays that each produce image information for injectioninto a corresponding waveguide 440 b, 438 b, 436 b, 434 b, 432 b,respectively. In some other embodiments, the image injection devices420, 422, 424, 426, 428 are the output ends of a single multiplexeddisplay which may, e.g., pipe image information via one or more opticalconduits (such as fiber optic cables) to each of the image injectiondevices 420, 422, 424, 426, 428.

A controller 460 controls the operation of the stacked waveguideassembly 480 and the image injection devices 420, 422, 424, 426, 428.The controller 460 includes programming (e.g., instructions in anon-transitory computer-readable medium) that regulates the timing andprovision of image information to the waveguides 440 b, 438 b, 436 b,434 b, 432 b. In some embodiments, the controller 460 may be a singleintegral device, or a distributed system connected by wired or wirelesscommunication channels. The controller 460 may be part of the processingmodules 260 or 270 (illustrated in FIG. 2) in some embodiments.

The waveguides 440 b, 438 b, 436 b, 434 b, 432 b may be configured topropagate light within each respective waveguide by total internalreflection (TIR). The waveguides 440 b, 438 b, 436 b, 434 b, 432 b mayeach be planar or have another shape (e.g., curved), with major top andbottom surfaces and edges extending between those major top and bottomsurfaces. In the illustrated configuration, the waveguides 440 b, 438 b,436 b, 434 b, 432 b may each include light extracting optical elements440 a, 438 a, 436 a, 434 a, 432 a that are configured to extract lightout of a waveguide by redirecting the light, propagating within eachrespective waveguide, out of the waveguide to output image informationto the eye 410. Extracted light may also be referred to as outcoupledlight, and light extracting optical elements may also be referred to asoutcoupling optical elements. An extracted beam of light is outputted bythe waveguide at locations at which the light propagating in thewaveguide strikes a light redirecting element. The light extractingoptical elements (440 a, 438 a, 436 a, 434 a, 432 a) may, for example,be reflective or diffractive optical features. While illustrateddisposed at the bottom major surfaces of the waveguides 440 b, 438 b,436 b, 434 b, 432 b for ease of description and drawing clarity, in someembodiments, the light extracting optical elements 440 a, 438 a, 436 a,434 a, 432 a may be disposed at the top or bottom major surfaces, or maybe disposed directly in the volume of the waveguides 440 b, 438 b, 436b, 434 b, 432 b. In some embodiments, the light extracting opticalelements 440 a, 438 a, 436 a, 434 a, 432 a may be formed in a layer ofmaterial that is attached to a transparent substrate to form thewaveguides 440 b, 438 b, 436 b, 434 b, 432 b. In some other embodiments,the waveguides 440 b, 438 b, 436 b, 434 b, 432 b may be a monolithicpiece of material and the light extracting optical elements 440 a, 438a, 436 a, 434 a, 432 a may be formed on a surface or in the interior ofthat piece of material.

With continued reference to FIG. 4, as discussed herein, each waveguide440 b, 438 b, 436 b, 434 b, 432 b is configured to output light to forman image corresponding to a particular depth plane. For example, thewaveguide 432 b nearest the eye may be configured to deliver collimatedlight, as injected into such waveguide 432 b, to the eye 410. Thecollimated light may be representative of the optical infinity focalplane. The next waveguide up 434 b may be configured to send outcollimated light which passes through the first lens 452 (e.g., anegative lens) before it can reach the eye 410. First lens 452 may beconfigured to create a slight convex wavefront curvature so that theeye/brain interprets light coming from that next waveguide up 434 b ascoming from a first focal plane closer inward toward the eye 410 fromoptical infinity. Similarly, the third up waveguide 436 b passes itsoutput light through both the first lens 452 and second lens 454 beforereaching the eye 410. The combined optical power of the first and secondlenses 452 and 454 may be configured to create another incrementalamount of wavefront curvature so that the eye/brain interprets lightcoming from the third waveguide 436 b as coming from a second focalplane that is even closer inward toward the person from optical infinitythan was light from the next waveguide up 434 b.

The other waveguide layers (e.g., waveguides 438 b, 440 b) and lenses(e.g., lenses 456, 458) are similarly configured, with the highestwaveguide 440 b in the stack sending its output through all of thelenses between it and the eye for an aggregate focal powerrepresentative of the closest focal plane to the person. To compensatefor the stack of lenses 458, 456, 454, 452 when viewing/interpretinglight coming from the world 470 on the other side of the stackedwaveguide assembly 480, a compensating lens layer 430 may be disposed atthe top of the stack to compensate for the aggregate power of the lensstack 458, 456, 454, 452 below. Such a configuration provides as manyperceived focal planes as there are available waveguide/lens pairings.Both the light extracting optical elements of the waveguides and thefocusing aspects of the lenses may be static (e.g., not dynamic orelectro-active). In some alternative embodiments, either or both may bedynamic using electro-active features.

With continued reference to FIG. 4, the light extracting opticalelements 440 a, 438 a, 436 a, 434 a, 432 a may be configured to bothredirect light out of their respective waveguides and to output thislight with the appropriate amount of divergence or collimation for aparticular depth plane associated with the waveguide. As a result,waveguides having different associated depth planes may have differentconfigurations of light extracting optical elements, which output lightwith a different amount of divergence depending on the associated depthplane. In some embodiments, as discussed herein, the light extractingoptical elements 440 a, 438 a, 436 a, 434 a, 432 a may be volumetric orsurface features, which may be configured to output light at specificangles. For example, the light extracting optical elements 440 a, 438 a,436 a, 434 a, 432 a may be volume holograms, surface holograms, and/ordiffraction gratings. Light extracting optical elements, such asdiffraction gratings, are described in U.S. Patent Publication No.2015/0178939, published Jun. 25, 2015, which is incorporated byreference herein in its entirety.

In some embodiments, the light extracting optical elements 440 a, 438 a,436 a, 434 a, 432 a are diffractive features that form a diffractionpattern, or “diffractive optical element” (also referred to herein as a“DOE”). Preferably, the DOE has a relatively low diffraction efficiencyso that only a portion of the light of the beam is deflected away towardthe eye 410 with each intersection of the DOE, while the rest continuesto move through a waveguide via total internal reflection. The lightcarrying the image information can thus be divided into a number ofrelated exit beams that exit the waveguide at a multiplicity oflocations and the result is a fairly uniform pattern of exit emissiontoward the eye 304 for this particular collimated beam bouncing aroundwithin a waveguide.

In some embodiments, one or more DOEs may be switchable between “on”state in which they actively diffract, and “off” state in which they donot significantly diffract. For instance, a switchable DOE may comprisea layer of polymer dispersed liquid crystal, in which microdropletscomprise a diffraction pattern in a host medium, and the refractiveindex of the microdroplets can be switched to substantially match therefractive index of the host material (in which case the pattern doesnot appreciably diffract incident light) or the microdroplet can beswitched to an index that does not match that of the host medium (inwhich case the pattern actively diffracts incident light).

In some embodiments, the number and distribution of depth planes ordepth of field may be varied dynamically based on the pupil sizes ororientations of the eyes of the viewer. Depth of field may changeinversely with a viewer's pupil size. As a result, as the sizes of thepupils of the viewer's eyes decrease, the depth of field increases suchthat one plane that is not discernible because the location of thatplane is beyond the depth of focus of the eye may become discernible andappear more in focus with reduction of pupil size and commensurate withthe increase in depth of field. Likewise, the number of spaced apartdepth planes used to present different images to the viewer may bedecreased with the decreased pupil size. For example, a viewer may notbe able to clearly perceive the details of both a first depth plane anda second depth plane at one pupil size without adjusting theaccommodation of the eye away from one depth plane and to the otherdepth plane. These two depth planes may, however, be sufficiently infocus at the same time to the user at another pupil size withoutchanging accommodation.

In some embodiments, the display system may vary the number ofwaveguides receiving image information based upon determinations ofpupil size or orientation, or upon receiving electrical signalsindicative of particular pupil size or orientation. For example, if theuser's eyes are unable to distinguish between two depth planesassociated with two waveguides, then the controller 460 (which may be anembodiment of the local processing and data module 260) can beconfigured or programmed to cease providing image information to one ofthese waveguides. Advantageously, this may reduce the processing burdenon the system, thereby increasing the responsiveness of the system. Inembodiments in which the DOEs for a waveguide are switchable between theon and off states, the DOEs may be switched to the off state when thewaveguide does receive image information.

In some embodiments, it may be desirable to have an exit beam meet thecondition of having a diameter that is less than the diameter of the eyeof a viewer. However, meeting this condition may be challenging in viewof the variability in size of the viewer's pupils. In some embodiments,this condition is met over a wide range of pupil sizes by varying thesize of the exit beam in response to determinations of the size of theviewer's pupil. For example, as the pupil size decreases, the size ofthe exit beam may also decrease. In some embodiments, the exit beam sizemay be varied using a variable aperture.

The wearable system 400 can include an outward-facing imaging system 464(e.g., a digital camera) that images a portion of the world 470. Thisportion of the world 470 may be referred to as the field of view (FOV)of a world camera and the imaging system 464 is sometimes referred to asan FOV camera. The FOV of the world camera may or may not be the same asthe FOV of a viewer 210 which encompasses a portion of the world 470 theviewer 210 perceives at a given time. For example, in some situations,the FOV of the world camera may be larger than the viewer 210 of theviewer 210 of the wearable system 400. The entire region available forviewing or imaging by a viewer may be referred to as the field of regard(FOR). The FOR may include 4π steradians of solid angle surrounding thewearable system 400 because the wearer can move his body, head, or eyesto perceive substantially any direction in space. In other contexts, thewearer's movements may be more constricted, and accordingly the wearer'sFOR may subtend a smaller solid angle. Images obtained from theoutward-facing imaging system 464 can be used to track gestures made bythe user (e.g., hand or finger gestures), detect objects in the world470 in front of the user, and so forth.

The wearable system 400 can include an audio sensor 232, e.g., amicrophone, to capture ambient sound. As described above, in someembodiments, one or more other audio sensors can be positioned toprovide stereo sound reception useful to the determination of locationof a speech source. The audio sensor 232 can comprise a directionalmicrophone, as another example, which can also provide such usefuldirectional information as to where the audio source is located. Thewearable system 400 can use information from both the outward-facingimaging system 464 and the audio sensor 230 in locating a source ofspeech, or to determine an active speaker at a particular moment intime, etc. For example, the wearable system 400 can use the voicerecognition alone or in combination with a reflected image of thespeaker (e.g., as seen in a mirror) to determine the identity of thespeaker. As another example, the wearable system 400 can determine aposition of the speaker in an environment based on sound acquired fromdirectional microphones. The wearable system 400 can parse the soundcoming from the speaker's position with speech recognition algorithms todetermine the content of the speech and use voice recognition techniquesto determine the identity (e.g., name or other demographic information)of the speaker.

The wearable system 400 can also include an inward-facing imaging system466 (e.g., a digital camera), which observes the movements of the user,such as the eye movements and the facial movements. The inward-facingimaging system 466 may be used to capture images of the eye 410 todetermine the size and/or orientation of the pupil of the eye 304. Theinward-facing imaging system 466 can be used to obtain images for use indetermining the direction the user is looking (e.g., eye pose) or forbiometric identification of the user (e.g., via iris identification). Insome embodiments, at least one camera may be utilized for each eye, toseparately determine the pupil size or eye pose of each eyeindependently, thereby allowing the presentation of image information toeach eye to be dynamically tailored to that eye. In some otherembodiments, the pupil diameter or orientation of only a single eye 410(e.g., using only a single camera per pair of eyes) is determined andassumed to be similar for both eyes of the user. The images obtained bythe inward-facing imaging system 466 may be analyzed to determine theuser's eye pose or mood, which can be used by the wearable system 400 todecide which audio or visual content should be presented to the user.The wearable system 400 may also determine head pose (e.g., headposition or head orientation) using sensors such as IMUs,accelerometers, gyroscopes, etc.

The wearable system 400 can include a user input device 466 by which theuser can input commands to the controller 460 to interact with thewearable system 400. For example, the user input device 466 can includea trackpad, a touchscreen, a joystick, a multiple degree-of-freedom(DOF) controller, a capacitive sensing device, a game controller, akeyboard, a mouse, a directional pad (D-pad), a wand, a haptic device, atotem (e.g., functioning as a virtual user input device), and so forth.A multi-DOF controller can sense user input in some or all possibletranslations (e.g., left/right, forward/backward, or up/down) orrotations (e.g., yaw, pitch, or roll) of the controller. A multi-DOFcontroller which supports the translation movements may be referred toas a 3DOF while a multi-DOF controller which supports the translationsand rotations may be referred to as 6DOF. In some cases, the user mayuse a finger (e.g., a thumb) to press or swipe on a touch-sensitiveinput device to provide input to the wearable system 400 (e.g., toprovide user input to a user interface provided by the wearable system400). The user input device 466 may be held by the user's hand duringthe use of the wearable system 400. The user input device 466 can be inwired or wireless communication with the wearable system 400.

Other Components of the Wearable System

In many implementations, the wearable system may include othercomponents in addition or in alternative to the components of thewearable system described above. The wearable system may, for example,include one or more haptic devices or components. The haptic devices orcomponents may be operable to provide a tactile sensation to a user. Forexample, the haptic devices or components may provide a tactilesensation of pressure or texture when touching virtual content (e.g.,virtual objects, virtual tools, other virtual constructs). The tactilesensation may replicate a feel of a physical object which a virtualobject represents, or may replicate a feel of an imagined object orcharacter (e.g., a dragon) which the virtual content represents. In someimplementations, haptic devices or components may be worn by the user(e.g., a user wearable glove). In some implementations, haptic devicesor components may be held by the user.

The wearable system may, for example, include one or more physicalobjects which are manipulable by the user to allow input or interactionwith the wearable system. These physical objects may be referred toherein as totems. Some totems may take the form of inanimate objects,such as for example, a piece of metal or plastic, a wall, a surface oftable. In certain implementations, the totems may not actually have anyphysical input structures (e.g., keys, triggers, joystick, trackball,rocker switch). Instead, the totem may simply provide a physicalsurface, and the wearable system may render a user interface so as toappear to a user to be on one or more surfaces of the totem. Forexample, the wearable system may render an image of a computer keyboardand trackpad to appear to reside on one or more surfaces of a totem. Forexample, the wearable system may render a virtual computer keyboard andvirtual trackpad to appear on a surface of a thin rectangular plate ofaluminum which serves as a totem. The rectangular plate does not itselfhave any physical keys or trackpad or sensors. However, the wearablesystem may detect user manipulation or interaction or touches with therectangular plate as selections or inputs made via the virtual keyboardor virtual trackpad. The user input device 466 (shown in FIG. 4) may bean embodiment of a totem, which may include a trackpad, a touchpad, atrigger, a joystick, a trackball, a rocker or virtual switch, a mouse, akeyboard, a multi-degree-of-freedom controller, or another physicalinput device. A user may use the totem, alone or in combination withposes, to interact with the wearable system or other users.

Examples of haptic devices and totems usable with the wearable devices,HMD, and display systems of the present disclosure are described in U.S.Patent Publication No. 2015/0016777, which is incorporated by referenceherein in its entirety.

Example Processes of User Interactions with a Wearable System

FIG. 5 is a process flow diagram of an example of a method 500 forinteracting with a virtual user interface. The method 500 may beperformed by the wearable system described herein. Embodiments of themethod 500 can be used by the wearable system to detect persons ordocuments in the FOV of the wearable system.

At block 510, the wearable system may identify a particular UI. The typeof UI may be predetermined by the user. The wearable system may identifythat a particular UI needs to be populated based on a user input (e.g.,gesture, visual data, audio data, sensory data, direct command, etc.).The UI can be specific to a security scenario where the wearer of thesystem is observing users who present documents to the wearer (e.g., ata travel checkpoint). At block 520, the wearable system may generatedata for the virtual UI. For example, data associated with the confines,general structure, shape of the UI etc., may be generated. In addition,the wearable system may determine map coordinates of the user's physicallocation so that the wearable system can display the UI in relation tothe user's physical location. For example, if the UI is body centric,the wearable system may determine the coordinates of the user's physicalstance, head pose, or eye pose such that a ring UI can be displayedaround the user or a planar UI can be displayed on a wall or in front ofthe user. In the security context described herein, the UI may bedisplayed as if the UI were surrounding the traveler who is presentingdocuments to the wearer of the system, so that the wearer can readilyview the UI while looking at the traveler and the traveler's documents.If the UI is hand centric, the map coordinates of the user's hands maybe determined. These map points may be derived through data receivedthrough the FOV cameras, sensory input, or any other type of collecteddata.

At block 530, the wearable system may send the data to the display fromthe cloud or the data may be sent from a local database to the displaycomponents. At block 540, the UI is displayed to the user based on thesent data. For example, a light field display can project the virtual UIinto one or both of the user's eyes. Once the virtual UI has beencreated, the wearable system may simply wait for a command from the userto generate more virtual content on the virtual UI at block 550. Forexample, the UI may be a body centric ring around the user's body or thebody of a person in the user's environment (e.g., a traveler). Thewearable system may then wait for the command (a gesture, a head or eyemovement, voice command, input from a user input device, etc.), and ifit is recognized (block 560), virtual content associated with thecommand may be displayed to the user (block 570).

Examples of Avatar Rendering in Mixed Reality

A wearable system may employ various mapping related techniques in orderto achieve high depth of field in the rendered light fields. In mappingout the virtual world, it is advantageous to know all the features andpoints in the real world to accurately portray virtual objects inrelation to the real world. To this end, FOV images captured from usersof the wearable system can be added to a world model by including newpictures that convey information about various points and features ofthe real world. For example, the wearable system can collect a set ofmap points (such as 2D points or 3D points) and find new map points torender a more accurate version of the world model. The world model of afirst user can be communicated (e.g., over a network such as a cloudnetwork) to a second user so that the second user can experience theworld surrounding the first user.

FIG. 6A is a block diagram of another example of a wearable system whichcan comprise an avatar processing and rendering system 690 in a mixedreality environment. The wearable system 600 may be part of the wearablesystem 200 shown in FIG. 2. In this example, the wearable system 600 cancomprise a map 620, which may include at least a portion of the data inthe map database 710 (shown in FIG. 7). The map may partly residelocally on the wearable system, and may partly reside at networkedstorage locations accessible by wired or wireless network (e.g., in acloud system). A pose process 610 may be executed on the wearablecomputing architecture (e.g., processing module 260 or controller 460)and utilize data from the map 620 to determine position and orientationof the wearable computing hardware or user. Pose data may be computedfrom data collected on the fly as the user is experiencing the systemand operating in the world. The data may comprise images, data fromsensors (such as inertial measurement units, which generally compriseaccelerometer and gyroscope components) and surface informationpertinent to objects in the real or virtual environment.

A sparse point representation may be the output of a simultaneouslocalization and mapping (e.g., SLAM or vSLAM, referring to aconfiguration wherein the input is images/visual only) process. Thesystem can be configured to not only find out where in the world thevarious components are, but what the world is made of. Pose may be abuilding block that achieves many goals, including populating the mapand using the data from the map.

In one embodiment, a sparse point position may not be completelyadequate on its own, and further information may be needed to produce amultifocal AR, VR, or MR experience. Dense representations, generallyreferring to depth map information, may be utilized to fill this gap atleast in part. Such information may be computed from a process referredto as Stereo 640, wherein depth information is determined using atechnique such as triangulation or time-of-flight sensing. Imageinformation and active patterns (such as infrared patterns created usingactive projectors), images acquired from image cameras, or handgestures/totem 650 may serve as input to the Stereo process 640. Asignificant amount of depth map information may be fused together, andsome of this may be summarized with a surface representation. Forexample, mathematically definable surfaces may be efficient (e.g.,relative to a large point cloud) and digestible inputs to otherprocessing devices like game engines. Thus, the output of the stereoprocess (e.g., a depth map) 640 may be combined in the fusion process630. Pose 610 may be an input to this fusion process 630 as well, andthe output of fusion 630 becomes an input to populating the map process620. Sub-surfaces may connect with each other, such as in topographicalmapping, to form larger surfaces, and the map becomes a large hybrid ofpoints and surfaces.

To resolve various aspects in a mixed reality process 660, variousinputs may be utilized. For example, in the embodiment depicted in FIG.6A, Game parameters may be inputs to determine that the user of thesystem is playing a monster battling game with one or more monsters atvarious locations, monsters dying or running away under variousconditions (such as if the user shoots the monster), walls or otherobjects at various locations, and the like. The world map may includeinformation regarding the location of the objects or semanticinformation of the objects (e.g., classifications such as whether theobject is flat or round, horizontal or vertical, a table or a lamp,etc.) and the world map can be another valuable input to mixed reality.Pose relative to the world becomes an input as well and plays a key roleto almost any interactive system.

Controls or inputs from the user are another input to the wearablesystem 600. As described herein, user inputs can include visual input,gestures, totems, audio input, sensory input, etc. In order to movearound or play a game, for example, the user may need to instruct thewearable system 600 regarding what he or she wants to do. Beyond justmoving oneself in space, there are various forms of user controls thatmay be utilized. In one embodiment, a totem (e.g. a user input device),or an object such as a toy gun may be held by the user and tracked bythe system. The system preferably will be configured to know that theuser is holding the item and understand what kind of interaction theuser is having with the item (e.g., if the totem or object is a gun, thesystem may be configured to understand location and orientation, as wellas whether the user is clicking a trigger or other sensed button orelement which may be equipped with a sensor, such as an IMU, which mayassist in determining what is going on, even when such activity is notwithin the field of view of any of the cameras.)

Hand gesture tracking or recognition may also provide input information.The wearable system 600 may be configured to track and interpret handgestures for button presses, for gesturing left or right, stop, grab,hold, etc. For example, in one configuration, the user may want to flipthrough emails or a calendar in a non-gaming environment, or do a “fistbump” with another person or player. The wearable system 600 may beconfigured to leverage a minimum amount of hand gesture, which may ormay not be dynamic. For example, the gestures may be simple staticgestures like open hand for stop, thumbs up for ok, thumbs down for notok; or a hand flip right, or left, or up/down for directional commands.

Eye tracking is another input (e.g., tracking where the user is lookingto control the display technology to render at a specific depth orrange). In one embodiment, vergence of the eyes may be determined usingtriangulation, and then using a vergence/accommodation model developedfor that particular person, accommodation may be determined. Eyetracking can be performed by the eye camera(s) to determine eye gaze(e.g., direction or orientation of one or both eyes). Other techniquescan be used for eye tracking such as, e.g., measurement of electricalpotentials by electrodes placed near the eye(s) (e.g.,electrooculography).

Speech tracking can be another input can be used alone or in combinationwith other inputs (e.g., totem tracking, eye tracking, gesture tracking,etc.). Speech tracking may include speech recognition, voicerecognition, alone or in combination. The system 600 can include anaudio sensor (e.g., a microphone) that receives an audio stream from theenvironment. The system 600 can incorporate voice recognition technologyto determine who is speaking (e.g., whether the speech is from thewearer of the ARD or another person or voice (e.g., a recorded voicetransmitted by a loudspeaker in the environment)) as well as speechrecognition technology to determine what is being said. The local data &processing module 260 or the remote processing module 270 can processthe audio data from the microphone (or audio data in another stream suchas, e.g., a video stream being watched by the user) to identify contentof the speech by applying various speech recognition algorithms, suchas, e.g., hidden Markov models, dynamic time warping (DTW)-based speechrecognitions, neural networks, deep learning algorithms such as deepfeedforward and recurrent neural networks, end-to-end automatic speechrecognitions, machine learning algorithms (described with reference toFIG. 7), or other algorithms that uses acoustic modeling or languagemodeling, etc.

The local data & processing module 260 or the remote processing module270 can also apply voice recognition algorithms which can identify theidentity of the speaker, such as whether the speaker is the user 210 ofthe wearable system 600 or another person with whom the user isconversing. Some example voice recognition algorithms can includefrequency estimation, hidden Markov models, Gaussian mixture models,pattern matching algorithms, neural networks, matrix representation,Vector Quantization, speaker diarisation, decision trees, and dynamictime warping (DTW) technique. Voice recognition techniques can alsoinclude anti-speaker techniques, such as cohort models, and worldmodels. Spectral features may be used in representing speakercharacteristics. The local data & processing module or the remote dataprocessing module 270 can use various machine learning algorithmsdescribed with reference to FIG. 7 to perform the voice recognition.

An implementation of a wearable system can use these user controls orinputs via a UI. UI elements (e.g., controls, popup windows, bubbles,data entry fields, etc.) can be used, for example, to dismiss a displayof information, e.g., graphics or semantic information of an object.

With regard to the camera systems, the example wearable system 600 shownin FIG. 6A can include three pairs of cameras: a relative wide FOV orpassive SLAM pair of cameras arranged to the sides of the user's face, adifferent pair of cameras oriented in front of the user to handle thestereo imaging process 640 and also to capture hand gestures andtotem/object tracking in front of the user's face. The FOV cameras andthe pair of cameras for the stereo process 640 may be a part of theoutward-facing imaging system 464 (shown in FIG. 4). The wearable system600 can include eye tracking cameras (which may be a part of aninward-facing imaging system 462 shown in FIG. 4) oriented toward theeyes of the user in order to triangulate eye vectors and otherinformation. The wearable system 600 may also comprise one or moretextured light projectors (such as infrared (IR) projectors) to injecttexture into a scene.

The wearable system 600 can comprise an avatar processing and renderingsystem 690. The avatar processing and rendering system 690 can beconfigured to generate, update, animate, and render an avatar based oncontextual information. Some or all of the avatar processing andrendering system 690 can be implemented as part of the local processingand data module 260 or the remote processing module 262, 264 alone or incombination. In various embodiments, multiple avatar processing andrendering systems 690 (e.g., as implemented on different wearabledevices) can be used for rendering the virtual avatar 670. For example,a first user's wearable device may be used to determine the first user'sintent, while a second user's wearable device can determine an avatar'scharacteristics and render the avatar of the first user based on theintent received from the first user's wearable device. The first user'swearable device and the second user's wearable device (or other suchwearable devices) can communicate via a network, for example, as will bedescribed with reference to FIGS. 9A and 9B.

FIG. 6B illustrates an example avatar processing and rendering system690. The example avatar processing and rendering system 690 can comprisea 3D model processing system 680, a contextual information analysissystem 688, an avatar autoscaler 692, an intent mapping system 694, ananatomy adjustment system 698, a stimuli response system 696, alone orin combination. The system 690 is intended to illustrate functionalitiesfor avatar processing and rendering and is not intended to be limiting.For example, in certain implementations, one or more of these systemsmay be part of another system. For example, portions of the contextualinformation analysis system 688 may be part of the avatar autoscaler692, intent mapping system 694, stimuli response system 696, or anatomyadjustment system 698, individually or in combination.

The contextual information analysis system 688 can be configured todetermine environment and object information based on one or more devicesensors described with reference to FIGS. 2 and 3. For example, thecontextual information analysis system 688 can analyze environments andobjects (including physical or virtual objects) of a user's environmentor an environment in which the user's avatar is rendered, using imagesacquired by the outward-facing imaging system 464 of the user or theviewer of the user's avatar. The contextual information analysis system688 can analyze such images alone or in combination with a data acquiredfrom location data or world maps (e.g., maps 620, 710, 910) to determinethe location and layout of objects in the environments. The contextualinformation analysis system 688 can also access biological features ofthe user or human in general for animating the virtual avatar 670realistically. For example, the contextual information analysis system688 can generate a discomfort curve which can be applied to the avatarsuch that a portion of the user's avatar's body (e.g., the head) is notat an uncomfortable (or unrealistic) position with respect to the otherportions of the user's body (e.g., the avatar's head is not turned 270degrees). In certain implementations, one or more object recognizers 708(shown in FIG. 7) may be implemented as part of the contextualinformation analysis system 688.

The avatar autoscaler 692, the intent mapping system 694, and thestimuli response system 696, and anatomy adjustment system 698 can beconfigured to determine the avatar's characteristics based on contextualinformation. Some example characteristics of the avatar can include thesize, appearance, position, orientation, movement, pose, expression,etc. The avatar autoscaler 692 can be configured to automatically scalethe avatar such that the user does not have to look at the avatar at anuncomfortable pose. For example, the avatar autoscaler 692 can increaseor decrease the size of the avatar to bring the avatar to the user's eyelevel such that the user does not need to look down at the avatar orlook up at the avatar respectively. The intent mapping system 694 candetermine an intent of a user's interaction and map the intent to anavatar (rather than the exact user interaction) based on the environmentthat the avatar is rendered in. For example, an intent of a first usermay be to communicate with a second user in a telepresence session (see,e.g., FIG. 9B). Typically, two people face each other whencommunicating. The intent mapping system 694 of the first user'swearable system can determine that such a face-to-face intent existsduring the telepresence session and can cause the first user's wearablesystem to render the second user's avatar to be facing the first user.If the second user were to physically turn around, instead of renderingthe second user's avatar in a turned position (which would cause theback of the second user's avatar to be rendered to the first user), thefirst user's intent mapping system 694 can continue to render the secondavatar's face to the first user, which is the inferred intent of thetelepresence session (e.g., face-to-face intent in this example).

The stimuli response system 696 can identify an object of interest inthe environment and determine an avatar's response to the object ofinterest. For example, the stimuli response system 696 can identify asound source in an avatar's environment and automatically turn theavatar to look at the sound source. The stimuli response system 696 canalso determine a threshold termination condition. For example, thestimuli response system 696 can cause the avatar to go back to itsoriginal pose after the sound source disappears or after a period oftime has elapsed.

The anatomy adjustment system 698 can be configured to adjust the user'spose based on biological features. For example, the anatomy adjustmentsystem 698 can be configured to adjust relative positions between theuser's head and the user's torso or between the user's upper body andlower body based on a discomfort curve.

The 3D model processing system 680 can be configured to animate andcause the display 220 to render a virtual avatar 670. The 3D modelprocessing system 680 can include a virtual character processing system682 and a movement processing system 684. The virtual characterprocessing system 682 can be configured to generate and update a 3Dmodel of a user (for creating and animating the virtual avatar). Themovement processing system 684 can be configured to animate the avatar,such as, e.g., by changing the avatar's pose, by moving the avatararound in a user's environment, or by animating the avatar's facialexpressions, etc. As will further be described herein, the virtualavatar can be animated using rigging techniques. In some embodiments, anavatar is represented in two parts: a surface representation (e.g., adeformable mesh) that is used to render the outward appearance of thevirtual avatar and a hierarchical set of interconnected joints (e.g., acore skeleton) for animating the mesh. In some implementations, thevirtual character processing system 682 can be configured to edit orgenerate surface representations, while the movement processing system684 can be used to animate the avatar by moving the avatar, deformingthe mesh, etc.

Examples of Mapping a User's Environment

FIG. 7 is a block diagram of an example of an MR environment 700. The MRenvironment 700 may be configured to receive input (e.g., visual input702 from the user's wearable system, stationary input 704 such as roomcameras, sensory input 706 from various sensors, gestures, totems, eyetracking, user input from the user input device 466 etc.) from one ormore user wearable systems (e.g., wearable system 200 or display system220) or stationary room systems (e.g., room cameras, etc.). The wearablesystems can use various sensors (e.g., accelerometers, gyroscopes,temperature sensors, movement sensors, depth sensors, GPS sensors,inward-facing imaging system, outward-facing imaging system, etc.) todetermine the location and various other attributes of the environmentof the user. This information may further be supplemented withinformation from stationary cameras in the room that may provide imagesor various cues from a different point of view. The image data acquiredby the cameras (such as the room cameras and/or the cameras of theoutward-facing imaging system) may be reduced to a set of mappingpoints.

One or more object recognizers 708 can crawl through the received data(e.g., the collection of points) and recognize or map points, tagimages, attach semantic information to objects with the help of a mapdatabase 710. The map database 710 may comprise various points collectedover time and their corresponding objects. The various devices and themap database can be connected to each other through a network (e.g.,LAN, WAN, etc.) to access the cloud.

Based on this information and collection of points in the map database,the object recognizers 708 a to 708 n may recognize objects in anenvironment. For example, the object recognizers can recognize faces,persons, windows, walls, user input devices, televisions, documents(e.g., travel tickets, driver's license, passport as described in thesecurity examples herein), other objects in the user's environment, etc.One or more object recognizers may be specialized for object withcertain characteristics. For example, the object recognizer 708 a may beused to recognizer faces, while another object recognizer may be usedrecognize documents.

The object recognitions may be performed using a variety of computervision techniques. For example, the wearable system can analyze theimages acquired by the outward-facing imaging system 464 (shown in FIG.4) to perform scene reconstruction, event detection, video tracking,object recognition (e.g., persons or documents), object pose estimation,facial recognition (e.g., from a person in the environment or an imageon a document), learning, indexing, motion estimation, or image analysis(e.g., identifying indicia within documents such as photos, signatures,identification information, travel information, etc.), and so forth. Oneor more computer vision algorithms may be used to perform these tasks.Non-limiting examples of computer vision algorithms include:Scale-invariant feature transform (SIFT), speeded up robust features(SURF), oriented FAST and rotated BRIEF (ORB), binary robust invariantscalable keypoints (BRISK), fast retina keypoint (FREAK), Viola-Jonesalgorithm, Eigenfaces approach, Lucas-Kanade algorithm, Horn-Schunkalgorithm, Mean-shift algorithm, visual simultaneous location andmapping (vSLAM) techniques, a sequential Bayesian estimator (e.g.,Kalman filter, extended Kalman filter, etc.), bundle adjustment,Adaptive thresholding (and other thresholding techniques), IterativeClosest Point (ICP), Semi Global Matching (SGM), Semi Global BlockMatching (SGBM), Feature Point Histograms, various machine learningalgorithms (such as e.g., support vector machine, k-nearest neighborsalgorithm, Naive Bayes, neural network (including convolutional or deepneural networks), or other supervised/unsupervised models, etc.), and soforth.

The object recognitions can additionally or alternatively be performedby a variety of machine learning algorithms. Once trained, the machinelearning algorithm can be stored by the HMD. Some examples of machinelearning algorithms can include supervised or non-supervised machinelearning algorithms, including regression algorithms (such as OrdinaryLeast Squares Regression), instance-based algorithms (such as LearningVector Quantization), decision tree algorithms (such as classificationand regression trees), Bayesian algorithms (such as Naive Bayes),clustering algorithms (such as k-means clustering), association rulelearning algorithms (such as a-priori algorithms), artificial neuralnetwork algorithms (such as Perceptron), deep learning algorithms (suchas Deep Boltzmann Machine, or deep neural network), dimensionalityreduction algorithms (such as Principal Component Analysis), ensemblealgorithms (such as Stacked Generalization), and/or other machinelearning algorithms. In some embodiments, individual models can becustomized for individual data sets. For example, the wearable devicecan generate or store a base model. The base model may be used as astarting point to generate additional models specific to a data type(e.g., a particular user in the telepresence session), a data set (e.g.,a set of additional images obtained of the user in the telepresencesession), conditional situations, or other variations. In someembodiments, the wearable HMD can be configured to utilize a pluralityof techniques to generate models for analysis of the aggregated data.Other techniques may include using pre-defined thresholds or datavalues.

Based on this information and collection of points in the map database,the object recognizers 708 a to 708 n may recognize objects andsupplement objects with semantic information to give life to theobjects. For example, if the object recognizer recognizes a set ofpoints to be a door, the system may attach some semantic information(e.g., the door has a hinge and has a 90 degree movement about thehinge). If the object recognizer recognizes a set of points to be amirror, the system may attach semantic information that the mirror has areflective surface that can reflect images of objects in the room. Thesemantic information can include affordances of the objects as describedherein. For example, the semantic information may include a normal ofthe object. The system can assign a vector whose direction indicates thenormal of the object. Over time the map database grows as the system(which may reside locally or may be accessible through a wirelessnetwork) accumulates more data from the world. Once the objects arerecognized, the information may be transmitted to one or more wearablesystems. For example, the MR environment 700 may include informationabout a scene happening in California. The environment 700 may betransmitted to one or more users in New York. Based on data receivedfrom an FOV camera and other inputs, the object recognizers and othersoftware components can map the points collected from the variousimages, recognize objects etc., such that the scene may be accurately“passed over” to a second user, who may be in a different part of theworld. The environment 700 may also use a topological map forlocalization purposes.

FIG. 8 is a process flow diagram of an example of a method 800 ofrendering virtual content in relation to recognized objects. The method800 describes how a virtual scene may be presented to a user of thewearable system. The user may be geographically remote from the scene.For example, the user may be in New York, but may want to view a scenethat is presently going on in California, or may want to go on a walkwith a friend who resides in California.

At block 810, the wearable system may receive input from the user andother users regarding the environment of the user. This may be achievedthrough various input devices, and knowledge already possessed in themap database. The user's FOV camera, sensors, GPS, eye tracking, etc.,convey information to the system at block 810. The system may determinesparse points based on this information at block 820. The sparse pointsmay be used in determining pose data (e.g., head pose, eye pose, bodypose, or hand gestures) that can be used in displaying and understandingthe orientation and position of various objects in the user'ssurroundings. The object recognizers 708 a-708 n may crawl through thesecollected points and recognize one or more objects using a map databaseat block 830. This information may then be conveyed to the user'sindividual wearable system at block 840, and the desired virtual scenemay be accordingly displayed to the user at block 850. For example, thedesired virtual scene (e.g., user in CA) may be displayed at theappropriate orientation, position, etc., in relation to the variousobjects and other surroundings of the user in New York.

Example Communications Among Multiple Wearable Systems

FIG. 9A schematically illustrates an overall system view depictingmultiple user devices interacting with each other. The computingenvironment 900 includes user devices 930 a, 930 b, 930 c. The userdevices 930 a, 930 b, and 930 c can communicate with each other througha network 990. The user devices 930 a-930 c can each include a networkinterface to communicate via the network 990 with a remote computingsystem 920 (which may also include a network interface 971). The network990 may be a LAN, WAN, peer-to-peer network, radio, Bluetooth, or anyother network. The computing environment 900 can also include one ormore remote computing systems 920. The remote computing system 920 mayinclude server computer systems that are clustered and located atdifferent geographic locations. The user devices 930 a, 930 b, and 930 cmay communicate with the remote computing system 920 via the network990.

The remote computing system 920 may include a remote data repository 980which can maintain information about a specific user's physical and/orvirtual worlds. Data storage 980 can store information related to users,users' environment (e.g., world maps of the user's environment), orconfigurations of avatars of the users. The remote data repository maybe an embodiment of the remote data repository 280 shown in FIG. 2. Theremote computing system 920 may also include a remote processing module970. The remote processing module 970 may be an embodiment of the remoteprocessing module 270 shown in FIG. 2. The remote processing module 970may include one or more processors which can communicate with the userdevices (930 a, 930 b, 930 c) and the remote data repository 980. Theprocessors can process information obtained from user devices and othersources. In some implementations, at least a portion of the processingor storage can be provided by the local processing and data module 260(as shown in FIG. 2). The remote computing system 920 may enable a givenuser to share information about the specific user's own physical and/orvirtual worlds with another user.

The user device may be a wearable device (such as an HMD or an ARD), acomputer, a mobile device, or any other devices alone or in combination.For example, the user devices 930 b and 930 c may be an embodiment ofthe wearable system 200 shown in FIG. 2 (or the wearable system 400shown in FIG. 4) which can be configured to present AR/VR/MR content.

One or more of the user devices can be used with the user input device466 shown in FIG. 4. A user device can obtain information about the userand the user's environment (e.g., using the outward-facing imagingsystem 464 shown in FIG. 4). The user device and/or remote computingsystem 1220 can construct, update, and build a collection of images,points and other information using the information obtained from theuser devices. For example, the user device may process raw informationacquired and send the processed information to the remote computingsystem 1220 for further processing. The user device may also send theraw information to the remote computing system 1220 for processing. Theuser device may receive the processed information from the remotecomputing system 1220 and provide final processing before projecting tothe user. The user device may also process the information obtained andpass the processed information to other user devices. The user devicemay communicate with the remote data repository 1280 while processingacquired information. Multiple user devices and/or multiple servercomputer systems may participate in the construction and/or processingof acquired images.

The information on the physical worlds may be developed over time andmay be based on the information collected by different user devices.Models of virtual worlds may also be developed over time and be based onthe inputs of different users. Such information and models can sometimesbe referred to herein as a world map or a world model. As described withreference to FIGS. 6 and 7, information acquired by the user devices maybe used to construct a world map 910. The world map 910 may include atleast a portion of the map 620 described in FIG. 6A. Various objectrecognizers (e.g. 708 a, 708 b, 708 c . . . 708 n) may be used torecognize objects and tag images, as well as to attach semanticinformation to the objects. These object recognizers are also describedin FIG. 7.

The remote data repository 980 can be used to store data and tofacilitate the construction of the world map 910. The user device canconstantly update information about the user's environment and receiveinformation about the world map 910. The world map 910 may be created bythe user or by someone else. As discussed herein, user devices (e.g. 930a, 930 b, 930 c) and remote computing system 920, alone or incombination, may construct and/or update the world map 910. For example,a user device may be in communication with the remote processing module970 and the remote data repository 980. The user device may acquireand/or process information about the user and the user's environment.The remote processing module 970 may be in communication with the remotedata repository 980 and user devices (e.g. 930 a, 930 b, 930 c) toprocess information about the user and the user's environment. Theremote computing system 920 can modify the information acquired by theuser devices (e.g. 930 a, 930 b, 930 c), such as, e.g. selectivelycropping a user's image, modifying the user's background, adding virtualobjects to the user's environment, annotating a user's speech withauxiliary information, etc. The remote computing system 920 can send theprocessed information to the same and/or different user devices.

Examples of a Telepresence Session

FIG. 9B depicts an example where two users of respective wearablesystems are conducting a telepresence session. Two users (named Alice912 and Bob 914 in this example) are shown in this figure. The two usersare wearing their respective wearable devices 902 and 904 which caninclude an HMD described with reference to FIG. 2 (e.g., the displaydevice 220 of the system 200) for representing a virtual avatar of theother user in the telepresence session. The two users can conduct atelepresence session using the wearable device. Note that the verticalline in FIG. 9B separating the two users is intended to illustrate thatAlice 912 and Bob 914 may (but need not) be in two different locationswhile they communicate via telepresence (e.g., Alice may be inside heroffice in Atlanta while Bob is outdoors in Boston).

As described with reference to FIG. 9A, the wearable devices 902 and 904may be in communication with each other or with other user devices andcomputer systems. For example, Alice's wearable device 902 may be incommunication with Bob's wearable device 904, e.g., via the network 990(shown in FIG. 9A). The wearable devices 902 and 904 can track theusers' environments and movements in the environments (e.g., via therespective outward-facing imaging system 464, or one or more locationsensors) and speech (e.g., via the respective audio sensor 232). Thewearable devices 902 and 904 can also track the users' eye movements orgaze based on data acquired by the inward-facing imaging system 462. Insome situations, the wearable device can also capture or track a user'sfacial expressions or other body movements (e.g., arm or leg movements)where a user is near a reflective surface and the outward-facing imagingsystem 464 can obtain reflected images of the user to observe the user'sfacial expressions or other body movements.

A wearable device can use information acquired of a first user and theenvironment to animate a virtual avatar that will be rendered by asecond user's wearable device to create a tangible sense of presence ofthe first user in the second user's environment. For example, thewearable devices 902 and 904, the remote computing system 920, alone orin combination, may process Alice's images or movements for presentationby Bob's wearable device 904 or may process Bob's images or movementsfor presentation by Alice's wearable device 902. As further describedherein, the avatars can be rendered based on contextual information suchas, e.g., a user's intent, an environment of the user or an environmentin which the avatar is rendered, or other biological features of ahuman.

Although the examples only refer to two users, the techniques describedherein should not be limited to two users. Multiple users (e.g., two,three, four, five, six, or more) using wearables (or other telepresencedevices) may participate in a telepresence session. A particular user'swearable device can present to that particular user the avatars of theother users during the telepresence session. Further, while the examplesin this figure show users as standing in an environment, the users arenot required to stand. Any of the users may stand, sit, kneel, lie down,walk or run, or be in any position or movement during a telepresencesession. The user may also be in a physical environment other thandescribed in examples herein. The users may be in separate environmentsor may be in the same environment while conducting the telepresencesession. Not all users are required to wear their respective HMDs in thetelepresence session. For example, Alice 912 may use other imageacquisition and display devices such as a webcam and computer screenwhile Bob 914 wears the wearable device 904.

Examples of a Virtual Avatar

FIG. 10 illustrates an example of an avatar as perceived by a user of awearable system. The example avatar 1000 shown in FIG. 10 can be anavatar of Alice 912 (shown in FIG. 9B) standing behind a physical plantin a room. An avatar can include various characteristics, such as forexample, size, appearance (e.g., skin color, complexion, hair style,clothes, facial features, such as wrinkles, moles, blemishes, pimples,dimples, etc.), position, orientation, movement, pose, expression, etc.These characteristics may be based on the user associated with theavatar (e.g., the avatar 1000 of Alice may have some or allcharacteristics of the actual person Alice 912). As further describedherein, the avatar 1000 can be animated based on contextual information,which can include adjustments to one or more of the characteristics ofthe avatar 1000. Although generally described herein as representing thephysical appearance of the person (e.g., Alice), this is forillustration and not limitation. Alice's avatar could represent theappearance of another real or fictional human being besides Alice, apersonified object, a creature, or any other real or fictitiousrepresentation. Further, the plant in FIG. 10 need not be physical, butcould be a virtual representation of a plant that is presented to theuser by the wearable system. Also, additional or different virtualcontent than shown in FIG. 10 could be presented to the user.

Examples of Rigging Systems for Virtual Characters

An animated virtual character, such as a human avatar, can be wholly orpartially represented in computer graphics as a polygon mesh. A polygonmesh, or simply “mesh” for short, is a collection of points in a modeledthree-dimensional space. The mesh can form a polyhedral object whosesurfaces define the body or shape of the virtual character (or a portionthereof). While meshes can include any number of points (withinpractical limits which may be imposed by available computing power),finer meshes with more points are generally able to portray morerealistic virtual characters with finer details that may closelyapproximate real life people, animals, objects, etc. FIG. 10 shows anexample of a mesh 1010 around an eye of the avatar 1000.

Each point in the mesh can be defined by a coordinate in the modeledthree-dimensional space. The modeled three-dimensional space can be, forexample, a Cartesian space addressed by (x, y, z) coordinates. Thepoints in the mesh are the vertices of the polygons which make up thepolyhedral object. Each polygon represents a surface, or face, of thepolyhedral object and is defined by an ordered set of vertices, with thesides of each polygon being straight line edges connecting the orderedset of vertices. In some cases, the polygon vertices in a mesh maydiffer from geometric polygons in that they are not necessarily coplanarin 3D graphics. In addition, the vertices of a polygon in a mesh may becollinear, in which case the polygon has zero area (referred to as adegenerate polygon).

In some embodiments, a mesh is made up of three-vertex polygons (i.e.,triangles or “tris” for short) or four-vertex polygons (i.e.,quadrilaterals or “quads” for short). However, higher-order polygons canalso be used in some meshes. Meshes are typically quad-based in directcontent creation (DCC) applications (e.g., applications such as Maya®(available from Autodesk, Inc.) or Houdini® (available from Side EffectsSoftware Inc.) which are primarily designed for creating andmanipulating 3D computer graphics), whereas meshes are typicallytri-based in real-time applications.

To animate a virtual character, its mesh can be deformed by moving someor all of its vertices to new positions in space at various instants intime. The deformations can represent both large-scale movements (e.g.,movement of limbs) and fine movements (e.g., facial movements). Theseand other deformations can be based on real-world models (e.g.,photogrammetric scans of real humans performing body movements,articulations, facial contortions, expressions, etc.), art-directeddevelopment (which may be based on real-world sampling), combinations ofthe same, or other techniques. In the early days of computer graphics,mesh deformations could be accomplished manually by independentlysetting new positions for the vertices, but given the size andcomplexity of modern meshes it is typically desirable to producedeformations using automated systems and processes. The control systems,processes, and techniques for producing these deformations are referredto as rigging, or simply “the rig.” The example avatar processing andrendering system 690 of FIG. 6B includes a 3D model processing system680 which can implement rigging.

The rigging for a virtual character can use skeletal systems to assistwith mesh deformations. A skeletal system includes a collection ofjoints which correspond to points of articulation for the mesh. In thecontext of rigging, joints are sometimes also referred to as “bones”despite the difference between these terms when used in the anatomicalsense. Joints in a skeletal system can move, or otherwise change, withrespect to one another according to transforms which can be applied tothe joints. The transforms can include translations or rotations inspace, as well as other operations. The joints can be assignedhierarchical relationships (e.g., parent-child relationships) withrespect to one another. These hierarchical relationships can allow onejoint to inherit transforms or other characteristics from another joint.For example, a child joint in a skeletal system can inherit a transformassigned to its parent joint so as to cause the child joint to movetogether with the parent joint.

A skeletal system for a virtual character can be defined with joints atappropriate positions, and with appropriate local axes of rotation,degrees of freedom, etc., to allow for a desired set of meshdeformations to be carried out. Once a skeletal system has been definedfor a virtual character, each joint can be assigned, in a process called“skinning,” an amount of influence over the various vertices in themesh. This can be done by assigning a weight value to each vertex foreach joint in the skeletal system. When a transform is applied to anygiven joint, the vertices under its influence can be moved, or otherwisealtered, automatically based on that joint transform by amounts whichcan be dependent upon their respective weight values.

A rig can include multiple skeletal systems. One type of skeletal systemis a core skeleton (also referred to as a low-order skeleton) which canbe used to control large-scale movements of the virtual character. Inthe case of a human avatar, for example, the core skeleton mightresemble the anatomical skeleton of a human. Although the core skeletonfor rigging purposes may not map exactly to an anatomically-correctskeleton, it may have a sub-set of joints in analogous locations withanalogous orientations and movement properties.

As briefly mentioned above, a skeletal system of joints can behierarchical with, for example, parent-child relationships among joints.When a transform (e.g., a change in position and/or orientation) isapplied to a particular joint in the skeletal system, the same transformcan be applied to all other lower-level joints within the samehierarchy. In the case of a rig for a human avatar, for example, thecore skeleton may include separate joints for the avatar's shoulder,elbow, and wrist. Among these, the shoulder joint may be assigned to thehighest level in the hierarchy, while the elbow joint can be assigned asa child of the shoulder joint, and the wrist joint can be assigned as achild of the elbow joint. Accordingly, when a particular translationand/or rotation transform is applied to the shoulder joint, the sametransform can also be applied to the elbow joint and the wrist jointsuch that they are translated and/or rotated in the same way as theshoulder.

Despite the connotations of its name, a skeletal system in a rig neednot necessarily represent an anatomical skeleton. In rigging, skeletalsystems can represent a wide variety of hierarchies used to controldeformations of the mesh. For example, hair can be represented as aseries of joints in a hierarchical chain; skin motions due to anavatar's facial contortions (which may represent expressions such assmiling, frowning, laughing, speaking, blinking, etc.) can berepresented by a series of facial joints controlled by a facial rig;muscle deformation can be modeled by joints; and motion of clothing canbe represented by a grid of joints.

The rig for a virtual character can include multiple skeletal systems,some of which may drive the movement of others. A lower-order skeletalsystem is one which drives one or more higher-order skeletal systems.Conversely, higher-order skeletal systems are ones which are driven orcontrolled by a lower-order skeletal system. For example, whereas themovements of the core skeleton of a character might be controlledmanually by an animator, the core skeleton can in turn drive or controlthe movements of a higher-order skeletal system. For example,higher-order helper joints—which may not have anatomical analogs in aphysical skeleton—can be provided to improve the mesh deformations whichresult from movements of the core skeleton. The transforms applied tothese and other joints in higher-order skeletal systems may be derivedalgorithmically from the transforms applied to the lower-order skeleton.Higher-order skeletons can represent, for example, muscles, skin, fat,clothing, hair, or any other skeletal system which does not requiredirect animation control. There can also be other types of higher-orderrigging elements, such as higher-order blendshapes which are controlledby a lower-order rigging element.

As already discussed, transforms can be applied to joints in skeletalsystems in order to carry out mesh deformations. In the context ofrigging, transforms include functions which accept one or more givenpoints in 3D space and produce an output of one or more new 3D points.For example, a transform can accept one or more 3D points which define ajoint and can output one or more new 3D points which specify thetransformed joint. Joint transforms can include, for example, atranslation component, a rotation component, and a scale component.

A translation is a transform which moves a set of one or more specifiedpoints in the modeled 3D space by a specified amount with no change inthe orientation or size of the set of points. A rotation is a transformwhich rotates a set of one or more specified points in the modeled 3Dspace about a specified axis by a specified amount (e.g., rotate everypoint in the mesh 45 degrees about the z-axis). An affine transform (or6 degree of freedom (DOF) transform) is one which only includestranslation(s) and rotation(s). Application of an affine transform canbe thought of as moving a set of one or more points in space withoutchanging its size, though the orientation can change.

Meanwhile, a scale transform is one which modifies one or more specifiedpoints in the modeled 3D space by scaling their respective coordinatesby a specified value. This changes the size and/or shape of thetransformed set of points. A uniform scale transform scales eachcoordinate by the same amount, whereas a non-uniform scale transform canscale the (x, y, z) coordinates of the specified points independently. Anon-uniform scale transform can be used, for example, to providesquashing and stretching effects, such as those which may result frommuscular action. Yet another type of transform is a shear transform. Ashear transform is one which modifies a set of one or more specifiedpoints in the modeled 3D space by translating a coordinate of the pointsby different amounts based on the distance of that coordinate from anaxis.

When a transform is applied to a joint to cause it to move, the verticesunder the influence of that joint are also moved. This results indeformations of the mesh. As discussed above, the process of assigningweights to quantify the influence each joint has over each vertex iscalled skinning (or sometimes “weight painting” or “skin weighting”).The weights are typically values between 0 (meaning no influence) and 1(meaning complete influence). Some vertices in the mesh may beinfluenced only by a single joint. In that case those vertices areassigned weight values of 1 for that joint, and their positions arechanged based on transforms assigned to that specific joint but noothers. Other vertices in the mesh may be influenced by multiple joints.In that case, separate weights are assigned to those vertices for all ofthe influencing joints, with the sum of the weights for each vertexequaling 1. The positions of these vertices are changed based ontransforms assigned to all of their influencing joints.

Making weight assignments for all of the vertices in a mesh can beextremely labor intensive, especially as the number of joints increases.Balancing the weights to achieve desired mesh deformations in responseto transforms applied to the joints can be quite difficult for evenhighly trained artists. In the case of real-time applications, the taskcan be complicated further by the fact that many real-time systems alsoenforce limits on the number of joints (generally 8 or fewer) which canbe weighted to a specific vertex. Such limits are typically imposed forthe sake of efficiency in the graphics processing unit (GPU).

The term skinning also refers to the process of actually deforming themesh, using the assigned weights, based on transforms applied to thejoints in a skeletal system. For example, a series of core skeletonjoint transforms may be specified by an animator to produce a desiredcharacter movement (e.g., a running movement or a dance step). Whentransforms are applied to one or more of the joints, new positions arecalculated for the vertices under the influence of the transformedjoints. The new position for any given vertex is typically computed as aweighted average of all the joint transforms which influence thatparticular vertex. There are many algorithms used for computing thisweighted average, but the most common, and the one used in mostreal-time applications due to its simplicity and ease of control, islinear blend skinning (LBS). In linear blend skinning, a new positionfor each vertex is calculated using each joint transform for which thatvertex has a non-zero weight. Then, the new vertex coordinates resultingfrom each of these joint transforms are averaged in proportion to therespective weights assigned to that vertex for each of the joints. Thereare well known limitations to LBS in practice, and much of the work inmaking high-quality rigs is devoted to finding and overcoming theselimitations. Many helper joint systems are designed specifically forthis purpose.

In addition to skeletal systems, “blendshapes” can also be used inrigging to produce mesh deformations. A blendshape (sometimes alsocalled a “morph target” or just a “shape”) is a deformation applied to aset of vertices in the mesh where each vertex in the set is moved aspecified amount in a specified direction based upon a weight. Eachvertex in the set may have its own custom motion for a specificblendshape, and moving the vertices in the set simultaneously willgenerate the desired shape. The custom motion for each vertex in ablendshape can be specified by a “delta,” which is a vector representingthe amount and direction of XYZ motion applied to that vertex.Blendshapes can be used to produce, for example, facial deformations tomove the eyes, lips, brows, nose, dimples, etc., just to name a fewpossibilities.

Blendshapes are useful for deforming the mesh in an art-directable way.They offer a great deal of control, as the exact shape can be sculptedor captured from a scan of a model. But the benefits of blendshapes comeat the cost of having to store the deltas for all the vertices in theblendshape. For animated characters with fine meshes and manyblendshapes, the amount of delta data can be significant.

Each blendshape can be applied to a specified degree by using blendshapeweights. These weights typically range from 0 (where the blendshape isnot applied at all) to 1 (where the blendshape is fully active). Forexample, a blendshape to move a character's eyes can be applied with asmall weight to move the eyes a small amount, or it can be applied witha large weight to create a larger eye movement.

The rig may apply multiple blendshapes in combinations with one anotherto achieve a desired complex deformation. For example, to produce asmile, the rig may apply blendshapes for lip corner pull, raising theupper lip, and lowering the lower lip, as well as moving the eyes,brows, nose, and dimples. The desired shape from combining two or moreblendshapes is known as a combination shape (or simply a “combo”).

One problem that can result from applying two blendshapes in combinationis that the blendshapes may operate on some of the same vertices. Whenboth blendshapes are active, the result is called a double transform or“going off-model.” The solution to this is typically a correctiveblendshape. A corrective blendshape is a special blendshape whichrepresents a desired deformation with respect to a currently applieddeformation rather than representing a desired deformation with respectto the neutral. Corrective blendshapes (or just “correctives”) can beapplied based upon the weights of the blendshapes they are correcting.For example, the weight for the corrective blendshape can be madeproportionate to the weights of the underlying blendshapes which triggerapplication of the corrective blendshape.

Corrective blendshapes can also be used to correct skinning anomalies orto improve the quality of a deformation. For example, a joint mayrepresent the motion of a specific muscle, but as a single transform itcannot represent all the non-linear behaviors of the skin, fat, andmuscle. Applying a corrective, or a series of correctives, as the muscleactivates can result in more pleasing and convincing deformations.

Rigs are built in layers, with lower, simpler layers often drivinghigher-order layers. This applies to both skeletal systems andblendshape deformations. For example, as already mentioned, the riggingfor an animated virtual character may include higher-order skeletalsystems which are controlled by lower-order skeletal systems. There aremany ways to control a higher-order skeleton or a blendshape based upona lower-order skeleton, including constraints, logic systems, andpose-based deformation.

A constraint is typically a system where a particular object or jointtransform controls one or more components of a transform applied toanother joint or object. There are many different types of constraints.For example, aim constraints change the rotation of the target transformto point in specific directions or at specific objects. Parentconstraints act as virtual parent-child relationships between pairs oftransforms. Position constraints constrain a transform to specificpoints or a specific object. Orientation constraints constrain atransform to a specific rotation of an object.

Logic systems are systems of mathematical equations which produce someoutputs given a set of inputs. These are specified, not learned. Forexample, a blendshape value might be defined as the product of two otherblendshapes (this is an example of a corrective shape known as acombination or combo shape).

Pose-based deformations can also be used to control higher-orderskeletal systems or blendshapes. The pose of a skeletal system isdefined by the collection of transforms (e.g., rotation(s) andtranslation(s)) for all the joints in that skeletal system. Poses canalso be defined for subsets of the joints in a skeletal system. Forexample, an arm pose could be defined by the transforms applied to theshoulder, elbow, and wrist joints. A pose space deformer (PSD) is asystem used to determine a deformation output for a particular posebased on one or more “distances” between that pose and a defined pose.These distances can be metrics which characterize how different one ofthe poses is from the other. A PSD can include a pose interpolation nodewhich, for example, accepts a set of joint rotations (defining a pose)as input parameters and in turn outputs normalized per-pose weights todrive a deformer, such as a blendshape. The pose interpolation node canbe implemented in a variety of ways, including with radial basisfunctions (RBFs). RBFs can perform a machine-learned mathematicalapproximation of a function. RBFs can be trained using a set of inputsand their associated expected outputs. The training data could be, forexample, multiple sets of joint transforms (which define particularposes) and the corresponding blendshapes to be applied in response tothose poses. Once the function is learned, new inputs (e.g., poses) canbe given and their expected outputs can be computed efficiently. RBFsare a subtype of artificial neural networks. RBFs can be used to drivehigher-level components of a rig based upon the state of lower-levelcomponents. For example, the pose of a core skeleton can drive helperjoints and correctives at higher levels.

These control systems can be chained together to perform complexbehaviors. As an example, an eye rig could contain two “look around”values for horizontal and vertical rotation. These values can be passedthrough some logic to determine the exact rotation of an eye jointtransform, which might in turn be used as an input to an RBF whichcontrols blendshapes that change the shape of the eyelid to match theposition of the eye. The activation values of these shapes might be usedto drive other components of a facial expression using additional logic,and so on.

The goal of rigging systems is typically to provide a mechanism toproduce pleasing, high-fidelity deformations based on simple,human-understandable control systems. In the case of real-timeapplications, the goal is typically to provide rigging systems which aresimple enough to run in real-time on, for example, a VR/AR/MR system200, while making as few compromises to the final quality as possible.In some embodiments, the 3D model processing system 680 executes arigging system to animate an avatar in a mixed reality environment 100in real-time to be interactive (with users of the VR/AR/MR system) andto provide appropriate, contextual avatar behavior (e.g., intent-basedbehavior) in the user's environment.

Examples of Systems and Methods for Facilitating Cross-ApplicationConfigurations of Virtual Characters

As just discussed, the rigging for a virtual character can involvecontrol systems for automated control of rigging elements (e.g.,higher-order rigging elements) based on various inputs. And sometimesthere are multiple, interleaved layers of control systems in the riggingfor a particular virtual character. In the context of this disclosure, arigging control system includes a set of one or more rules (e.g.,logical rules, mathematical rules, etc.) which determines an output forcontrolling (e.g., regulating, adjusting, specifying, selecting,invoking, or otherwise impacting) a rigging element, such as ahigher-order skeletal system or a higher-order blendshape, based on aninput associated with a lower-order rigging element or other source.Since rigging control systems can be very complex, various tools havebeen created for authoring and implementing them. These tools typicallyutilize application-specific rigging control protocols. A particularrigging control protocol may include an application-specific set of dataformats (including number types, text types, file types, units ofmeasure, etc.), data structures, functions (including commands,mathematical operations, etc.), computational units (e.g., nodes,classes, etc.), and/or programming languages. When differentapplications use different rigging control protocols, it is not possibleto directly transfer a rigging control system which has been authored inone application and then execute it in another application.

Digital content creation (DCC) applications are often used fordeveloping the rigging, including rigging control systems, for virtualcharacters. One example of such a DCC application is Autodesk Maya®. ADCC application can provide various tools for defining rigging elements,such as polygon meshes, skeletal systems, blendshapes, etc., and fordefining control systems for performing automated control of theserigging elements. The rigging control systems are built in the DCCapplication using its application-specific rigging control protocol.

Although DCC applications are well-suited for creating virtualcharacters and their associated rigging, they are typically notwell-suited for real-time display of virtual characters (includingreal-time execution of the associated character rigging) in a game orVR/AR/MR application, for example. Instead, real-time engines have beendeveloped for this purpose. One example of such a real-time engine isthe Unreal® Engine available from Epic Games. Real-time engines areprimarily designed to display finished rigging assets and are notwell-suited to authoring sophisticated rigging assets. While real-timeengines can include tools for creating rigging elements and/or riggingcontrol systems, they are usually not as robust as those which exist inDCC applications; it is significantly easier to specify, build, and testnew rigging assets, including rigging control systems, in a DCCapplication. Thus, real-time engines typically rely on DCC applicationsto provide virtual characters and their associated rigging. Thisrequires rigging assets to be transferred from a DCC application to areal-time engine.

Tools, such as the Filmbox (FBX®) format, exist for transferring meshes,blendshapes, skeletal systems, and animations between applications.However, no similar tool exists for transferring rigging control systemsbetween applications. While meshes, blendshapes, skeletal systems, andanimations can be well-defined in formats which can easily be portedbetween applications, a rigging control system is typically tightlycoupled to a specific application's data structures and conventions(e.g., the rigging control protocol used by the authoring application).Transferring rigging control systems from an authoring application to areal-time application therefore requires re-implementing the controlsystems in the real-time application environment in much the same way asoftware developer might re-implement an algorithm in multiple softwarelanguages to run in multiple applications and/or on multiple computingplatforms. However, re-implementing the rigging control systems for avirtual character can be a very difficult, time-consuming, and expensiveproposition due to their complexity and the difficulty of validatingparities between applications.

Systems and methods are described herein for advantageously implementingrigging control systems with cross-application functionality andtransferability. As discussed further herein, this can be accomplishedby providing a framework that can be embedded in an application, such asa DCC application or a real-time engine. The embedding application,whether it be a DCC application or a real-time engine, can implementrigging control systems according to a first rigging control protocol(e.g., the rigging control protocol that is native to that particularapplication). Meanwhile, the embedded framework can implement riggingcontrol systems according to a different second rigging controlprotocol.

The embedded framework can receive rigging control input(s) from theembedding application. The rigging control input(s) can represent, orotherwise be associated with, a request for a particular behavior fromthe rigging for a virtual character. The requested behavior can be, forexample, a particular character movement. The embedded framework canthen convert the rigging control input(s) so as to be compatible withthe second rigging control protocol which is used by the embeddedframework. For example, the embedded framework can convert riggingcontrol input values into mathematical representations which aresupported in the second rigging control protocol. The embedded frameworkcan include a rigging control evaluation system which then determinesone or more rigging control outputs by using the rigging controlinput(s) to evaluate the rigging control system(s). The rigging controloutput(s) can then be converted by the embedded framework so as to becompatible with the first rigging control protocol of the embeddingapplication. For example, the embedded framework can convert riggingcontrol output(s) into mathematical representations which are supportedin the first rigging control protocol, which is native to the embeddingapplication. The embedded framework can then pass the rigging controloutput(s) to the embedding application to be used to manipulate thevirtual character according to the behavior requested by, or otherwiseassociated with, the rigging control input(s).

A developer can use an authoring application programming interface (API)for designing and building rigging control systems in the embeddedframework according to the second rigging control protocol. The riggingcontrol systems can be defined using a control system descriptionlanguage. The authoring API may be designed to interface with, or bepart of, the embedded framework. Using the authoring API of the embeddedframework, rigging control systems can be authored according to thesecond rigging control protocol while still using design tools offeredby a DCC application in which the framework is embedded.

The embedded framework can write and read descriptions of the riggingcontrol systems to and from data files. In some embodiments, this can bedone using a serialization tool. For example, the rigging control systemdescriptions for a virtual character—which are defined according to thesecond rigging control protocol using the control system descriptionlanguage of the embedded framework—can be outputted in a data file whichcan be transferred from an authoring application, such as a DCCapplication, to a recipient application, such as a real-time engine.

The recipient application, too, can include an embedded framework thatimplements rigging control systems according to the second riggingcontrol protocol. For example, the embedded framework in the recipientapplication can include a rigging control evaluation system whichevaluates rigging control systems that are defined using the samecontrol system description language that is used by the embeddedframework in the authoring application. In addition, like the embeddedframework in the authoring application, the embedded framework in therecipient application can translate the rigging control input(s) fromthe recipient application so as to be compatible with the second riggingcontrol protocol. The rigging control evaluation system of the embeddedframework in the recipient application can then use the input(s) toevaluate the rigging control system(s) and the framework can translatethe rigging control output(s) so as to be compatible with the nativerigging control protocol of the recipient application. The recipientapplication can then use the rigging control output(s) to manipulate thevirtual character.

According to these systems and methods, a developer can advantageouslydevelop and test the rigging control system(s) for a virtual characterin an authoring application, such as a DCC application, which iswell-suited to that purpose. The developer can then transfer the virtualcharacter's rigging elements, including rigging control systems, to bedisplayed by another application, such as a real-time engine, which iswell-suited to that purpose. In this way, cross-application authoring,transfer, and execution of rigging control systems for virtualcharacters can be achieved.

Example Computing Environment for Cross-Application Rigging ControlSystems

FIG. 11 illustrates an example computing environment 1100 forcross-application implementations of rigging control systems. Theexample computing environment 1100 includes a DCC application 1140 and awearable VR/AR/MR device 200 with a real-time engine 1130. An example ofthe wearable VR/AR/MR device 200 is described herein with respect toFIG. 2. The DCC application 1140 and the real-time engine 1130 can eachbe implemented as software executing on one or more computing deviceswhich may have central processing units (CPU), graphics processing units(GPU), memory devices, and/or data stores.

The DCC application 1140 can be a computer application for creating,animating, modeling, simulating, and rendering rigging assets forvirtual characters. These rigging assets may be used in VR/AR/MRapplications, film, television, game development, etc. to providerealistic and high fidelity animated virtual characters. The DCCapplication 1140 can include various tools to allow a developer todefine rigging assets which make up an animated virtual character. Forexample, a developer can use the DCC application 1140 to define a vertexmesh for the character, to create skeletal systems, and to skin thecharacter to create realistic movements with mesh deformations. Adeveloper can also use the DCC application 1140 to define one or morerigging control systems for the virtual character. A rigging controlsystem can include a set of one or more rules (e.g., logical rules,mathematical rules, etc.) which determines an output for controlling(e.g., regulating, adjusting, specifying, selecting, invoking, orotherwise impacting) a rigging element based on an input. The riggingcontrol input could be one or more values associated with a lower-orderrigging element, such as a core skeleton, or other source. Meanwhile,the rigging control output could be one or more values to controlhigher-order rigging elements, such as higher-order skeletal systems,higher-order blendshapes (e.g., correctives), etc.

Examples of behaviors which can be controlled by rigging control systemsinclude the following: controlling movement of a virtual character'smuscles, hair, or clothing based on the transforms (e.g., rotations)applied to the character's core skeleton; controlling the gaze directionof a virtual character's eyes, or the location of a body part of thecharacter, based on the location of an object; and controllingmovements, gestures, and/or expressions of a virtual character based onfeedback (e.g., from cameras or other sensors) regarding the movements,gestures, expressions, or other sensed physiological characteristics ofa human user. Many other controlled behaviors are also possible.

The DCC application 1140 may use a first rigging control protocol,including an application-specific set of data formats, data structures,functions, computational units (e.g., nodes, classes, etc.), and/orprogramming languages for defining rigging control systems. For example,the DCC application 1140 may include a node-based structure for definingand evaluating rigging control systems. Each of the nodes can implementone or more rigging control tasks.

The VR/AR/MR system 200 can execute an application which utilizes avirtual character. The application can be, for example, a gameapplication or a telepresence application with a virtual avatar. TheVR/AR/MR system 200 can display the virtual character using thereal-time engine 1130. The real-time engine 1130 can display the virtualcharacter by implementing and/or evaluating its rigging elements,including meshes, skeletal systems, blendshapes, animations, riggingcontrol systems, etc.

The DCC application 1140 can include Framework A 1150 a and thereal-time engine 1130 can include Framework B 1150 b. In someembodiments, these frameworks 1150 a, 1150 b may be specific to therespective application in which they are embedded. The frameworks 1150a, 1150 b can collectively enable cross-application authoring, transfer,and execution of rigging control systems for the virtual character. Theframeworks 1150 a, 1150 b can be respectively integrated into the DCCapplication 1140 and the real-time engine 1130 as, for example,plug-ins. In some embodiments, the DCC application 1140 is AutodeskMaya® and the real-time engine is Epic's Unreal® Engine.

In some embodiments, Framework A in the DCC application 1140 can createa data file 1154 which defines the rigging control systems for thevirtual character. The data file 1154 can also include other riggingassets, such as vertex meshes, skeletal systems, blendshapes,animations, etc. The data file 1154 can be communicated between the DCCapplication 1140 and the real-time engine 1130 via a communication link.Framework B in the real-time engine 1130 can then use the data file 1154to implement the rigging control systems to be used when displaying thevirtual character.

Example Framework for Transferring Control Systems

FIG. 12 illustrates an example of an embedded framework 1150 that can beused for cross-application authoring, transfer, and evaluation ofrigging control systems for a virtual character. The framework 1150 canbe embedded (e.g., as a plug-in) in an application 1202, such as a DCCapplication 1140 or a real-time engine 1130. The application 1202 canimplement rigging control systems according to a first rigging controlprotocol, while the framework 1150 implements rigging control systemsaccording to a different second rigging control protocol. The framework1150 can receive a rigging control input from the application 1212,process the input through a rigging control evaluation system 1220, andprovide a rigging control output to the application 1218.

Rigging Control System Description Language

The framework 1150 can define and evaluate rigging control systems inaccordance with a rigging control protocol which is different from thenative protocol used by the application 1202. In the rigging controlprotocol used by the framework 1150, rigging control systems can bedefined using a rigging control system description language. The riggingcontrol system description language can specify the inputs and outputsfor a rigging control system. The description language can also specifysupported data types for the inputs and outputs. These may includeintegers, floating point values, Boolean values, strings, etc. Therigging control system description language can also define supportedmathematical objects, such as XYZ vectors and quaternion values, whichcan be operated on by rigging control systems.

The rigging control system description language can also definemathematical and/or logical rules which can operate on supported inputs.The rules can be, for example, mathematical functions. Commonmathematical functions and rigging domain-specific functions can besupported. The rules can involve simple operations, such as performingarithmetic or Boolean logic on one or more rigging control inputs.Alternatively, the operations can be complex, such as evaluating aradial basis function using a set of core skeleton joint rotations asinputs, and outputting blendshape weights and/or deltas based on thepose of the core skeletal system. Many other operations are alsopossible. New functions can be created by defining them using any of avariety of programming languages, such as C++or Python, and registeringthem using the authoring tool 1240. The rigging control systemdescription language can be character rig-agnostic in that the languagecan be used to define rigging control systems for any type of virtualcharacter.

Rigging Control System Description(s)

The rigging control system description language can be used to createrigging control system descriptions 1222. The rigging control systemdescriptions 1222 define the logic associated with a given riggingcontrol system. For example, the rigging control system descriptions candescribe logic for controlling the movement and/or other behavior of avirtual character, given one or more input values, such as bydetermining blendshape weights, transforms for helper joints, etc. Eachrigging control system description 1222 can include, for example, a setof one or more mathematical/logical rules or operations to be evaluatedusing a designated rigging control input 1212. Some of these rules canreceive the output from another rule as their inputs. The control systemdescriptions collectively define the rigging control behaviorsassociated with the rig for a particular virtual character and aretherefore character rig-specific. However, the rigging control systemdescription(s) can be application-agnostic in that they can betransferred between a first application and a second application and canbe used by either, so long as the application includes the embeddedframework 1150. The rigging control system descriptions 1222 can beimplemented using a rigging control system description language, whichcan be any suitable computer programming language, including a customlanguage.

Rigging Control System Authoring Tool

A rigging control system authoring tool 1240 can be provided for use ingenerating the rigging control system descriptions 1222. The authoringtool 1240 can provide an API that can be called by the application 1202so that the design tools in the application 1202 can be used fordesigning rigging control system descriptions 1222. The authoring toolcan translate or otherwise convert rigging control system descriptionsfrom the embedding application 1202 to the control system descriptionlanguage used by the framework 1202. The authoring tool 1240 may bebuilt with various programming languages. Where the authoring tool 1240is built using the Python programming language, the authoring tool 1240can utilize Python's native ability to extend mathematical notations tonew types.

Rigging Control Evaluation System

The framework 1150 can also include a rigging control evaluation system1220. The rigging control evaluation system 1220 can be independent ofthe application 1202 and can operate according to a different riggingcontrol protocol. Thus, it may include data structures and usemathematical representations that are different from those used by theapplication 1202. The rigging control evaluation system 1220 can utilizerigging control input values supplied by the framework 1150 to determine(e.g., calculate, look-up, etc.) one or more rigging control outputvalues by evaluating one or more rigging control systems specified bythe control system description(s) 1222. The rigging control evaluationsystem 1220 then provides a resulting output to the framework 1150. Insome embodiments, the rigging control evaluation system 1220 is anode-based system, and the rigging control system descriptions can beimplemented as one or more nodes. The rigging control evaluation system1220 is character rig-agnostic in that it can evaluate control systemdescriptions 1222 for any virtual character. The rigging controlevaluation system 1220 can be implemented using any suitable computerprogramming language, such as, for example, the C++ language.

Framework

The framework 1150 can provide an encapsulation of the rigging controlevaluation system 1220. Since the rigging control evaluation system 1220uses a rigging control protocol which is different from the nativerigging control protocol used by the embedding application 1202, theframework 1150 can include translators 1214, 1216 for converting riggingcontrol inputs 1212 and outputs 1218 to be compatible with therespective rigging control protocols as the inputs and outputs arepassed between the application 1202 and the framework 1150. For example,the input translator 1214 can translate a rigging control input 1212from the application 1202 so as to be compatible with the riggingcontrol protocol used by the rigging control evaluation system 1220.Meanwhile, the output translator 1216 can translate a rigging controloutput from the rigging control evaluation system 1220 so as to becompatible with the rigging control protocol used by the embeddingapplication 1202.

In some embodiments, the translators 1214, 1216 can convert riggingcontrol inputs and outputs from one mathematical representation toanother. For example, Autodesk Maya® does not natively support the useof quaternions for calculating rotations. Instead, Autodesk Maya®calculates rotations using Euler angles. However, the use of quaternionsmay be preferred in the rigging control protocol used by the riggingcontrol evaluation system 1220. Therefore, the framework 1150 which isdesigned for use in Autodesk Maya® can use the input translator 1214 toconvert Maya-native Euler angles into quaternion representations for useby the rigging control evaluation system 1220. In some embodiments, theoperation of the output translator 1216 is the inverse of the operationperformed by the input translator 1214. For example, the outputtranslator 1216 can convert quaternion output values from the riggingcontrol evaluation system 1220 into Euler angles for use by Maya®.Similar translation mechanisms can also be used in other applications.

The translators 1214, 1216 can also perform translation operations whichare not mathematical. For example, the input translator 1214 can convertdata from a format used by the application 1202 to a format used by theframework 1150 (e.g., convert a text string from American Standard Codefor Information Interchange (Ascii) format to Unicode format, or viceversa), while the output translator 1216 can convert data back to theformat used by the application 1202. In addition, since some datastructures, such as matrices, hierarchical data, maps, etc., can beapplication-specific, the input translator 1214 can also convert a datastructure used by the application 1202 to a new data structure, or amodified data structure, used by the framework 1150 (e.g., convertmatrices from sparse to more dense representations, or vice versa), andthe output translator 1216 can convert that data structure back to theone used by the application 1202.

The rigging control input 1212 may be, for example, a joint transform(e.g., a rotation or translation), a blendshape weight, or a value froma sensor. But there are many other types of inputs that can also serveas the rigging control input 1212. In some embodiments, the riggingcontrol input 1212 can be associated with a lower-order rigging element.For example, the rigging control input 1212 could define acharacteristic of the lower-order rigging element. As an illustrativeexample, the rigging control input may be one or more transforms (e.g.,rotations) that are to be applied to one or more joints in a lower-orderskeletal system, such as the core skeleton. The rigging control input1212 could also be determined by a control system associated with alower-order rigging element. Or, the rigging control input 1212 couldcome from a source other than one associated with a lower-order riggingelement. For example, the rigging control input 1212 could come from acamera or other sensor that captures a movement, pose, or physiologicalcharacteristic from a user and then provides an input to a virtualcharacter's rigging to mimic or otherwise respond to the movement, pose,or physiological characteristic from the user. As one example, thesensor could detect blood flow to the user's face to determine when theuser is blushing. An input can then be provided to the virtualcharacter's rigging to mimic or otherwise respond to the blushing of theuser.

Additional examples of rigging control inputs 1212 include thefollowing: an input which is indicative of a state of some character orthing in a game or application (e.g., in a fighting game, a characterdamage value could be used as a rigging control input to adjust thecharacter's motion when hurt, to add damage deformations, such asbruises or swelling, or to change the virtual character's costume orappearance); an input which activates, deactivates, or modifies aparticular virtual character behavior based on some criterion (e.g., avirtual character's eyes could be switched from being controlled byanimation to being controlled to perform a behavior such as looking atsome other character or object based on an alpha value in the range from0 to 1 which transitions between the animated state and a controlledstate); an input which is indicative of performance by the real-timeengine 1130 (e.g., if frame rate drops below some lower threshold, arigging control input value could be provided to temporarily deactivatesome portion of the rigging for a virtual character in order to allowthe game application to maintain a desired range of latency); or aninput which activates a computationally-intensive higher-order riggingelement based on some criterion (e.g., only activating an element of afacial rig when the user is looking closely at the virtual character'sface). Many other example rigging control inputs 1212 are also possible.

The rigging control output 1218 can be used to control a riggingelement, such as a higher-order rigging element. For example, therigging control output could be one or more transforms (e.g., rotations)to be applied to one or more joints (e.g., helper joints) in ahigher-order skeletal system. The rigging control output couldalternatively control a blendshape, such as by invoking the blendshape,providing deltas for the blendshape, and/or providing a weight value forapplying the blendshape. The rigging control output can also be one thatcontrols some aspect of a game or other application based on a riggingcontrol system operation. For example, a rigging control system couldcontrol when a certain game element, sound, or haptic feedback isdeployed. There are also many other types of rigging control outputs.

The framework 1150 can be application-specific in that it can bedesigned to be interoperable with the design principles of the embeddingapplication 1202, which may vary from application to application. Forexample, the input translator 1214, the output translator 1216, and/orthe rigging control system authoring tool 1240 may vary depending uponthe rigging control protocol used by the embedding application 1202. Theframework 1150 is character rig-agnostic, however, in that it can beused to implement rigging control systems for any virtual character. Theframework 1150 can be implemented using, for example, the same computerprogramming language used to implement the application 1202 (e.g., theC++ programming language, when the application 1202 is Autodesk Maya® orEpic's Unreal® Engine).

Serialization Tool

The framework 1150 can also include a serialization tool 1230 forimporting or exporting a data file 1232 which includes the controlsystem descriptions 1222. The data file 1232 can also include otherrigging elements, such as meshes, skeletal systems, blend shapes,animations etc. Data serialization can be performed to format riggingelements such that they can be stored, transmitted, reconstructed, andused by multiple systems. The data file 1232 can be imported or exportedto any application 1202 which includes an instance of the embeddedframework 1150. Since the embedded framework 1150 uses the same riggingcontrol protocol regardless of the application 1202 in which it isembedded, this ability to import or export rigging control systemdescriptions 1222 in the data file 1232 allows rigging control systemsfor a particular virtual character to be transferred from oneapplication to another (e.g., from a DCC application to a real-timeengine). The data file 1232 may have, for example, a comma-separatedvalues (CSV) format, a JavaScript Object Notation (JSON) format, anExtensible Markup Language (XML) format, a YAML file format,combinations of the same, or the like. The serialization tool 1230 canbe implemented using, for example, the same computer programminglanguage used to implement the application 1202 or any other suitablelanguage, such as the Python programming language.

Example Flow Diagram for Cross-Application Transfers of Rigging ControlSystems

FIG. 13 illustrates an example flow diagram for cross-applicationtransfer of rigging control systems. The flow diagram 1300 involves twoapplications: Application A (1302 a) and Application B (1302 b).Applications A and B may respectively be any types of software toolscapable of creating, editing, and/or displaying virtual characters andtheir associated rigging assets. In some embodiments, Application A is aDCC application, such as Autodesk Maya®, while Application B is areal-time engine, such as Epic Unreal®.

Instances of the framework 1150 can be embedded into both Application Aand Application B. The framework 1150 can interface with the authoringtool 1240 for creating control system descriptions 1222 for a virtualcharacter. The control system descriptions 1222 can be exported (orimported) by a serialization tool 1230 to achieve cross-applicationtransfers of control system descriptions.

In the example flow diagram 1300 in FIG. 13, the authoring tool 1240,the serialization tools 1230 a, 1230 b, the rigging control systemdescription(s) 1222, and the data file 1232 correspond to instances ofthe corresponding features in FIG. 12. The control system descriptionscan be created in Application A and can later be used by Application Bfor controlling the rigging of the virtual character.

At (1), a developer can create rigging control system descriptions 1222in Application A via the authoring tool 1240. The control systemdescriptions 1222 can be used and tested within Application A, asdiscussed with respect to FIG. 12. At (2), the control systemdescriptions 1222 for the virtual character can be extracted by theserialization tool 1230 a. At (3), the serialization tool 1230 a canwrite the control system description 1222 into the data file 1232. At(4), the data file 1232 can be imported into Application B by theserialization tool 1230 b. At (5), Application B can load the controlsystem description 1222 into the application's embedded framework (e.g.,framework 1150 a or 1150 b). The control system descriptions 1222, onceimported into Application B, can be invoked for displaying the virtualcharacter. In embodiments where Application B can also create additionalcontrol system logic or edit the imported control system logic, theadditional or edited control system logic can also be exported fromApplication B and imported by application A using similar techniques.

Example Processes for Cross-Application Transfers of Control Systems

FIGS. 14A-14C illustrate example processes for cross-applicationauthoring, transfer, and evaluation of rigging control systems. Theexample processes 1400, 1430, 1450 may be performed by one or more ofthe computing systems shown in FIG. 11.

In FIG. 14A, at block 1430 of the process 1400, the computing system cancreate a first embedded framework object for a first application. Thecomputing system can also create control system descriptions associatedwith a virtual character in the first application. The first applicationmay be a DCC application for authoring rigging assets for virtualcharacters. To create the first embedded framework in the firstapplication, the computing system can load the embedded framework 1150into the first application. The first embedded framework may be, forexample, a plug-in for the first application. The plug-in can provideAPIs which can be called by the authoring tools of the first applicationfor creating rigging control systems for the virtual character. Forexample, the APIs can be used to set rigging control inputs, outputs,and rules associated with a behavior or action of the virtual character.The first embedded framework can be character-agnostic, and thus theAPIs for the first embedded framework can be used to create the riggingcontrol logic for various types of virtual characters.

FIG. 14B illustrates an example sub-process for block 1430 in thecontext of a DCC application having a node-based data structure. Atblock 1432, a developer can instantiate a framework object to containcharacter-specific data and to write rigging control logic for thevirtual character. For example, the framework object can be created fromthe plug-in class in Maya®. At block 1434, assets and logic for avirtual character can be configured in the first application. Forexample, a developer can define and configure nodes associated withcharacter-specific rigging control functions using authoring toolsprovided by the embedded framework and/or by the first application. Aseach node is completed, it can be automatically transferred to theembedded framework. At blocks 1436 and 1438, the configuration of thecharacter, including character-specific rigging elements and controllogic, can be stored in the framework object. The character-specificdata can be invoked in the first application for testing the virtualcharacter. The underlying rigging control logic can be stored as riggingcontrol system descriptions, which can be exported to anotherapplication and can be used without needing to rewrite the riggingcontrol system logic to be compatible with the native rigging controlprotocol of that application.

With reference back to FIG. 14A, at block 1450, the first applicationcan utilize the rigging control system descriptions. For example, adeveloper can test the rigging control system descriptions and otherrigging assets authored in the first application. As described withreference to FIG. 12, the first application can request a desiredbehavior from the character rig by providing rigging control inputsassociated with the desired behavior. The rigging control inputs can bepassed to the rigging control evaluation system of the embeddedframework, which can produce rigging control output values and pass themback to the first application to implement the desired characterbehavior. The developer can perform this process repeatedly and canmodify the control system descriptions via the authoring tool to attainthe desired character behaviors.

FIG. 14C illustrates an example sub-process for the block 1450. Thissub-process can be performed by the framework 1150 described in FIG. 12.At block 1452, the first application can request a desired behavior fromthe character's rig. The application can provide one or more riggingcontrol inputs associated with the request to the embedded framework.

At block 1454, the embedded framework 1150 can take the rigging controlinput and translate it into a language, data structure, format,representation, etc. that is recognizable by the rigging controlevaluation system 1220. As an example, the framework can translatecontrol values in the request from one mathematical representation(e.g., Euler angles) to another (e.g., quaternions) which isrecognizable by the rigging control evaluation system.

At block 1456, the rigging control evaluation system 1220 can use thetranslated input to evaluate a rigging control system description 1222to produce a rigging control output. The rigging control systemdescriptions can be configured to implement both lower-order andhigher-order rigging controls. In the case of higher-order riggingcontrols, the control inputs 1212 can be associated with lower-orderrigging elements within the character rig and the control outputs 1218can be used to control higher-order rigging elements. In the case oflower-order rigging controls, the control inputs 1212 can be providedfrom a source external to the character rig and the control outputs 1218can be used to control lower-order rigging elements.

The rigging control evaluation system 1220 can take one or more riggingcontrol inputs and can generate one or more rigging control outputs. Therigging control outputs can be used to control rigging elements beyondthe part of the character's rig that is directly associated with theinput. For example, one input 1212 for a particular rigging controlsystem may be a control value for tilting the character's head towardsthe shoulder. The output value(s) 1218 for high-order controls canspecify movements derived from the head tilting, such as movements forindividual vertebrae down the neck. The output values can includemultiple parameters, such as for translational movements and rotationalmovements in multiple directions. In situations such as this, a largenumber of rigging control output values can be generated from a smallnumber of rigging control input values.

As another example, an eye pupil could have two parameters, where oneparameter is for the up/down movements and the other parameter is forthe left/right movements. Either or both of these parameters can beadjusted to implement movement of the eye pupil. These two parameterscan also be provided as inputs 1212 to generate control outputs 1218 forhigher-order rigging elements. For example, the rigging control outputs1218 can be used to provide movements of the upper and/or lower eye lidsin conjunction with the eye pupil movements, which can make the virtualcharacter appear more realistic.

At block 1458, the rigging control output values can be translated bythe embedded framework into a language, data structure, format,representation, etc. that is recognizable by the first application. Atblock 1462, the translated output(s) can be communicated back to thefirst application, which can use the output(s) to implement theassociated behavior in the character rig.

With reference back to FIG. 14A, at block 1470 the embedded frameworkcan export application-agnostic rigging control system data from thefirst application. The application-agnostic data can include riggingcontrol system descriptions 1222, which may be exported as part ofcontrol systems data file 1232. The application-agnostic data can alsoinclude other rigging assets, such as skeletal systems and blendshapes.

At block 1490, the application-agnostic rigging control system data canoptionally be imported into a second instance of the embedded frameworkin a second application. The second application can have a nativerigging control protocol that is different than that of the firstapplication or the embedded framework. The second application can usethe rigging control system data to implement the virtual character inthe same manner as the first application. As a result, the controlsystem descriptions do not need to be reprogrammed in the secondapplication. The systems and methods described herein allow for riggingcontrol systems to be used any number of times by any number ofapplications.

Example Embodiments

1. A method comprising: receiving, from a first application whichimplements a first rigging control protocol, an input associated with arequest for a behavior from a rig for a virtual character; convertingthe input to be compatible with a second rigging control protocol thatis different from the first rigging control protocol; evaluating one ormore control systems, based on the input, to determine an output toprovide the requested behavior from the virtual character rig, the oneor more control systems being defined according to the second riggingcontrol protocol; converting the output to be compatible with the firstrigging control protocol; and providing the output to the firstapplication to manipulate the virtual character according to therequested behavior.

2. The method of Embodiment 1, wherein converting the input to becompatible with the second rigging control protocol comprises convertingthe input from a first mathematical representation utilized in the firstrigging control protocol to a second mathematical representationutilized in the second rigging control protocol.

3. The method of Embodiment 1, wherein the input specifies acharacteristic of a lower-order rigging element.

4. The method of Embodiment 3, wherein the lower-order rigging elementcomprises a core skeleton for the virtual character.

5. The method of Embodiment 4, wherein the input comprises a transformfor a joint in the core skeleton.

6. The method of Embodiment 1, wherein the output specifies acharacteristic of a higher-order rigging element.

7. The method of Embodiment 6, wherein the higher-order rigging elementcomprises a higher-order skeleton.

8. The method of Embodiment 7, wherein the output comprises a transformfor a joint in the higher-order skeleton.

9. The method of Embodiment 6, wherein the higher-order rigging elementcomprises a blendshape.

10. The method of Embodiment 9, wherein the output comprises ablendshape weight.

11. The method of Embodiment 1, wherein evaluating the one or morecontrol systems comprises evaluating a mathematical operation.

12. The method of Embodiment 11, wherein the mathematical operationcomprises a radial basis function.

13. The method of Embodiment 11, wherein the mathematical operationcomprises a Boolean operation.

14. The method of Embodiment 1, wherein the method is performed by aframework embedded in the first application.

15. The method of Embodiment 14, wherein the framework is a plug-in forthe first application.

16. The method of Embodiment 1, further comprising: preparing a datafile which specifies the one or more control systems; and outputting thedata file to a second application.

17. The method of Embodiment 16, wherein the first application is adigital content creation application whose primary function comprisescreation of virtual characters, and wherein the second application is areal-time engine.

18. The method of Embodiment 1, further comprising importing, from asecond application, a data file which specifies the one or more controlsystems.

19. The method of Embodiment 18, wherein the first application is areal-time engine, and wherein the second application is a digitalcontent creation application whose primary function comprises creationof virtual characters.

20. The method of Embodiment 19, further comprising executing thereal-time engine on an augmented reality display system.

21. The method of Embodiment 1, wherein the virtual character comprisesone or more rigging assets selected from the group comprising: a polygonmesh, a core skeletal system, a higher-order skeletal system, ablendshape, and an animation.

22. The method of Embodiment 1, wherein the first rigging controlprotocol comprises one or more data formats, data structures, functions,or computational units that are specific to the first application.

23. An apparatus comprising: a framework configured to receive, from afirst application which implements a first rigging control protocol, aninput associated with a request for a behavior from a rig for a virtualcharacter; a first translator configured to convert the input to becompatible with a second rigging control protocol that is different fromthe first rigging control protocol; a rigging control evaluation systemconfigured to evaluate one or more control systems, based on the input,to determine an output to provide the requested behavior from thevirtual character rig, the one or more control systems being definedaccording to the second rigging control protocol; and a secondtranslator configured to convert the output to be compatible with thefirst rigging control protocol, wherein the framework is configured toprovide the output to the first application to manipulate the virtualcharacter according to the requested behavior.

24. The apparatus of Embodiment 23, wherein converting the input to becompatible with the second rigging control protocol comprises convertingthe input from a first mathematical representation utilized in the firstrigging control protocol to a second mathematical representationutilized in the second rigging control protocol.

25. The apparatus of Embodiment 23, wherein the input specifies acharacteristic of a lower-order rigging element.

26. The apparatus of Embodiment 25, wherein the lower-order riggingelement comprises a core skeleton for the virtual character.

27. The apparatus of Embodiment 26, wherein the input comprises atransform for a joint in the core skeleton.

28. The apparatus of Embodiment 23, wherein the output specifies acharacteristic of a higher-order rigging element.

29. The apparatus of Embodiment 28, wherein the higher-order riggingelement comprises a higher-order skeleton.

30. The apparatus of Embodiment 29, wherein the output comprises atransform for a joint in the higher-order skeleton.

31. The apparatus of Embodiment 28, wherein the higher-order riggingelement comprises a blendshape.

32. The apparatus of Embodiment 31, wherein the output comprises ablendshape weight.

33. The apparatus of Embodiment 23, wherein evaluating the one or morecontrol systems comprises evaluating a mathematical operation.

34. The apparatus of Embodiment 33, wherein the mathematical operationcomprises a radial basis function.

35. The apparatus of Embodiment 33, wherein the mathematical operationcomprises a Boolean operation.

36. The apparatus of Embodiment 23, wherein the framework is embedded inthe first application.

37. The apparatus of Embodiment 36, wherein the framework is a plug-infor the first application.

38. The apparatus of Embodiment 23, wherein the framework is furtherconfigured to: prepare a data file which specifies the one or morecontrol systems; and output the data file to a second application.

39. The apparatus of Embodiment 38, wherein the first application is adigital content creation application whose primary function comprisescreation of virtual characters, and wherein the second application is areal-time engine.

40. The apparatus of Embodiment 23, wherein the framework is furtherconfigured to import, from a second application, a data file whichspecifies the one or more control systems.

41. The apparatus of Embodiment 40, wherein the first application is areal-time engine, and wherein the second application is a digitalcontent creation application whose primary function comprises creationof virtual characters.

42. The apparatus of Embodiment 41, wherein the framework is furtherconfigured to execute the real-time engine on an augmented realitydisplay system.

43. The apparatus of Embodiment 23, wherein the virtual charactercomprises one or more rigging assets selected from the group comprising:a polygon mesh, a core skeletal system, a higher-order skeletal system,a blendshape, and an animation.

44. The apparatus of Embodiment 23, wherein the first rigging controlprotocol comprises one or more data formats, data structures, functions,or computational units that are specific to the first application.

45. The apparatus of Embodiment 23, wherein the apparatus comprises anaugmented reality display system.

46. A method comprising: creating, in a first application whichimplements a first rigging control protocol, a rigging control systemdescription, the rigging control system description being definedaccording to a different second rigging control protocol, and therigging control system description specifying a rigging control inputand at least one rule for operating on the rigging control input toproduce a rigging control output; writing the rigging control systemdescription to a data file; and initiating transfer of the data file toa second application.

47. The method of Embodiment 46, wherein the method further comprisesevaluating the rigging control system description using a frameworkembedded in the first application.

48. The method of Embodiment 47, wherein the framework is embedded inthe first application as a plug-in.

49. The method of Embodiment 47, wherein the framework comprises anapplication programming interface to be called by the first applicationwhile creating the rigging control system description.

50. The method of Embodiment 47, wherein the method further comprisesconverting the rigging control input to be compatible with the secondrigging control protocol prior to evaluating the rigging control systemdescription.

51. The method of Embodiment 47, wherein the method further comprisesconverting the rigging control output to be compatible with the firstrigging control protocol after evaluating the rigging control systemdescription.

52. The method of Embodiment 46, wherein the rigging control inputspecifies a characteristic of a lower-order rigging element.

53. The method of Embodiment 52, wherein the lower-order rigging elementcomprises a core skeleton for a virtual character.

54. The method of Embodiment 53, wherein the rigging control inputcomprises a transform for a joint in the core skeleton.

55. The method of Embodiment 46, wherein the rigging control outputspecifies a characteristic of a higher-order rigging element.

56. The method of Embodiment 55, wherein the higher-order riggingelement comprises a higher-order skeleton.

57. The method of Embodiment 56, wherein the rigging control outputcomprises a transform for a joint in the higher-order skeleton.

58. The method of Embodiment 55, wherein the higher-order riggingelement comprises a blendshape.

59. The method of Embodiment 58, wherein the rigging control outputcomprises a blendshape weight.

60. The method of Embodiment 46, wherein the first application is adigital content creation application whose primary function comprisescreation of virtual characters, and wherein the second application is areal-time engine.

61. The method of Embodiment 46, wherein the rigging control outputcomprises a higher-order rigging control value or a lower-order riggingcontrol value.

62. The method of Embodiment 46, wherein the first rigging controlprotocol comprises one or more data formats, data structures, functions,or computational units that are specific to the first application.

63. An apparatus comprising: an authoring tool configured to create, ina first application which implements a first rigging control protocol, arigging control system description, the rigging control systemdescription being defined according to a different second riggingcontrol protocol, and the rigging control system description specifyinga rigging control input and at least one rule for operating on therigging control input to produce a rigging control output; and aserialization tool configured to write the rigging control systemdescription to a data file, and to initiate transfer of the data file toa second application.

64. The apparatus of Embodiment 63, wherein the apparatus furthercomprises a framework embedded in the first application, the frameworkbeing configured to evaluate the rigging control system description.

65. The apparatus of Embodiment 64, wherein the framework is embedded inthe first application as a plug-in.

66. The apparatus of Embodiment 64, wherein the authoring tool comprisesan application programming interface to be called by the firstapplication while creating the rigging control system description.

67. The apparatus of Embodiment 64, wherein the framework is configuredto convert the rigging control input to be compatible with the secondrigging control protocol prior to evaluating the rigging control systemdescription.

68. The apparatus of Embodiment 64, wherein the framework is furtherconfigured to convert the rigging control output to be compatible withthe first rigging control protocol after evaluating the rigging controlsystem description.

69. The apparatus of Embodiment 63, wherein the rigging control inputspecifies a characteristic of a lower-order rigging element.

70. The apparatus of Embodiment 69, wherein the lower-order riggingelement comprises a core skeleton for a virtual character.

71. The apparatus of Embodiment 70, wherein the rigging control inputcomprises a transform for a joint in the core skeleton.

72. The apparatus of Embodiment 63, wherein the rigging control outputspecifies a characteristic of a higher-order rigging element.

73. The apparatus of Embodiment 72, wherein the higher-order riggingelement comprises a higher-order skeleton.

74. The apparatus of Embodiment 73, wherein the rigging control outputcomprises a transform for a joint in the higher-order skeleton.

75. The apparatus of Embodiment 72, wherein the higher-order riggingelement comprises a blendshape.

76. The apparatus of Embodiment 75, wherein the rigging control outputcomprises a blendshape weight.

77. The apparatus of Embodiment 63, wherein the first application is adigital content creation application whose primary function comprisescreation of virtual characters, and wherein the second application is areal-time engine.

78. The apparatus of Embodiment 63, wherein the rigging control outputcomprises a higher-order rigging control value or a lower-order riggingcontrol value.

79. The apparatus of Embodiment 63, wherein the first rigging controlprotocol comprises one or more data formats, data structures, functions,or computational units that are specific to the first application.

80. The apparatus of Embodiment 63, wherein the apparatus comprises anaugmented reality display system.

81. A non-transitory computer-readable medium which, when read by acomputing device, causes the computing device to perform a methodcomprising: receiving, from a first application which implements a firstrigging control protocol, an input associated with a request for abehavior from a rig for a virtual character; converting the input to becompatible with a second rigging control protocol that is different fromthe first rigging control protocol; evaluating one or more controlsystems, based on the input, to determine an output to provide therequested behavior from the virtual character rig, the one or morecontrol systems being defined according to the second rigging controlprotocol; converting the output to be compatible with the first riggingcontrol protocol; and providing the output to the first application tomanipulate the virtual character according to the requested behavior.

82. The computer-readable medium of Embodiment 81, wherein convertingthe input to be compatible with the second rigging control protocolcomprises converting the input from a first mathematical representationutilized in the first rigging control protocol to a second mathematicalrepresentation utilized in the second rigging control protocol.

83. The computer-readable medium of Embodiment 81, wherein the inputspecifies a characteristic of a lower-order rigging element.

84. The computer-readable medium of Embodiment 83, wherein thelower-order rigging element comprises a core skeleton for the virtualcharacter.

85. The computer-readable medium of Embodiment 84, wherein the inputcomprises a transform for a joint in the core skeleton.

86. The computer-readable medium of Embodiment 81, wherein the outputspecifies a characteristic of a higher-order rigging element.

87. The computer-readable medium of Embodiment 86, wherein thehigher-order rigging element comprises a higher-order skeleton.

88. The computer-readable medium of Embodiment 87, wherein the outputcomprises a transform for a joint in the higher-order skeleton.

89. The computer-readable medium of Embodiment 86, wherein thehigher-order rigging element comprises a blendshape.

90. The computer-readable medium of Embodiment 89, wherein the outputcomprises a blendshape weight.

91. The computer-readable medium of Embodiment 81, wherein evaluatingthe one or more control systems comprises evaluating a mathematicaloperation.

92. The computer-readable medium of Embodiment 91, wherein themathematical operation comprises a radial basis function.

93. The computer-readable medium of Embodiment 91, wherein themathematical operation comprises a Boolean operation.

94. The computer-readable medium of Embodiment 81, wherein the method isperformed by a framework embedded in the first application.

95. The computer-readable medium of Embodiment 94, wherein the frameworkis a plug-in for the first application.

96. The computer-readable medium of Embodiment 81, wherein the methodfurther comprises: preparing a data file which specifies the one or morecontrol systems; and outputting the data file to a second application.

97. The computer-readable medium of Embodiment 96, wherein the firstapplication is a digital content creation application whose primaryfunction comprises creation of virtual characters, and wherein thesecond application is a real-time engine.

98. The computer-readable medium of Embodiment 81, wherein the methodfurther comprises importing, from a second application, a data filewhich specifies the one or more control systems.

99. The computer-readable medium of Embodiment 98, wherein the firstapplication is a real-time engine, and wherein the second application isa digital content creation application whose primary function comprisescreation of virtual characters.

100. The computer-readable medium of Embodiment 99, wherein the methodfurther comprises executing the real-time engine on an augmented realitydisplay system.

101. The computer-readable medium of Embodiment 81, wherein the virtualcharacter comprises one or more rigging assets selected from the groupcomprising: a polygon mesh, a core skeletal system, a higher-orderskeletal system, a blendshape, and an animation.

102. The computer-readable medium of Embodiment 81, wherein the firstrigging control protocol comprises one or more data formats, datastructures, functions, or computational units that are specific to thefirst application.

103. A non-transitory computer-readable medium which, when read by acomputing device, causes the computing device to perform a methodcomprising: creating, in a first application which implements a firstrigging control protocol, a rigging control system description, therigging control system description being defined according to adifferent second rigging control protocol, and the rigging controlsystem description specifying a rigging control input and at least onerule for operating on the rigging control input to produce a riggingcontrol output; writing the rigging control system description to a datafile; and initiating transfer of the data file to a second application.

104. The computer-readable medium of Embodiment 103, wherein the methodfurther comprises evaluating the rigging control system descriptionusing a framework embedded in the first application.

105. The computer-readable medium of Embodiment 104, wherein theframework is embedded in the first application as a plug-in.

106. The computer-readable medium of Embodiment 104, wherein theframework comprises an application programming interface to be called bythe first application while creating the rigging control systemdescription.

107. The computer-readable medium of Embodiment 104, wherein the methodfurther comprises converting the rigging control input to be compatiblewith the second rigging control protocol prior to evaluating the riggingcontrol system description.

108. The computer-readable medium of Embodiment 104, wherein the methodfurther comprises converting the rigging control output to be compatiblewith the first rigging control protocol after evaluating the riggingcontrol system description.

109. The computer-readable medium of Embodiment 103, wherein the riggingcontrol input specifies a characteristic of a lower-order riggingelement.

110. The computer-readable medium of Embodiment 109, wherein thelower-order rigging element comprises a core skeleton for a virtualcharacter.

111. The computer-readable medium of Embodiment 110, wherein the riggingcontrol input comprises a transform for a joint in the core skeleton.

112. The computer-readable medium of Embodiment 103, wherein the riggingcontrol output specifies a characteristic of a higher-order riggingelement.

113. The computer-readable medium of Embodiment 112, wherein thehigher-order rigging element comprises a higher-order skeleton.

114. The computer-readable medium of Embodiment 113, wherein the riggingcontrol output comprises a transform for a joint in the higher-orderskeleton.

115. The computer-readable medium of Embodiment 112, wherein thehigher-order rigging element comprises a blendshape.

116. The computer-readable medium of Embodiment 115, wherein the riggingcontrol output comprises a blendshape weight.

117. The computer-readable medium of Embodiment 103, wherein the firstapplication is a digital content creation application whose primaryfunction comprises creation of virtual characters, and wherein thesecond application is a real-time engine.

118. The computer-readable medium of Embodiment 103, wherein the riggingcontrol output comprises a higher-order rigging control value or alower-order rigging control value.

119. The computer-readable medium of Embodiment 103, wherein the firstrigging control protocol comprises one or more data formats, datastructures, functions, or computational units that are specific to thefirst application.

Other Considerations

Each of the processes, methods, and algorithms described herein and/ordepicted in the attached figures may be embodied in, and fully orpartially automated by, code modules executed by one or more physicalcomputing systems, hardware computer processors, application-specificcircuitry, and/or electronic hardware configured to execute specific andparticular computer instructions. For example, computing systems caninclude general purpose computers (e.g., servers) programmed withspecific computer instructions or special purpose computers, specialpurpose circuitry, and so forth. A code module may be compiled andlinked into an executable program, installed in a dynamic link library,or may be written in an interpreted programming language. In someimplementations, particular operations and methods may be performed bycircuitry that is specific to a given function.

Further, certain implementations of the functionality of the presentdisclosure are sufficiently mathematically, computationally, ortechnically complex that application-specific hardware or one or morephysical computing devices (utilizing appropriate specialized executableinstructions) may be necessary to perform the functionality, forexample, due to the volume or complexity of the calculations involved orto provide results substantially in real-time. For example, animationsor video may include many frames, with each frame having millions ofpixels, and specifically programmed computer hardware is necessary toprocess the video data to provide a desired image processing task orapplication in a commercially reasonable amount of time.

Code modules or any type of data may be stored on any type ofnon-transitory computer-readable medium, such as physical computerstorage including hard drives, solid state memory, random access memory(RAM), read only memory (ROM), optical disc, volatile or non-volatilestorage, combinations of the same and/or the like. The methods andmodules (or data) may also be transmitted as generated data signals(e.g., as part of a carrier wave or other analog or digital propagatedsignal) on a variety of computer-readable transmission mediums,including wireless-based and wired/cable-based mediums, and may take avariety of forms (e.g., as part of a single or multiplexed analogsignal, or as multiple discrete digital packets or frames). The resultsof the disclosed processes or process steps may be stored, persistentlyor otherwise, in any type of non-transitory, tangible computer storageor may be communicated via a computer-readable transmission medium.

Any processes, blocks, states, steps, or functionalities in flowdiagrams described herein and/or depicted in the attached figures shouldbe understood as potentially representing code modules, segments, orportions of code which include one or more executable instructions forimplementing specific functions (e.g., logical or arithmetical) or stepsin the process. The various processes, blocks, states, steps, orfunctionalities can be combined, rearranged, added to, deleted from,modified, or otherwise changed from the illustrative examples providedherein. In some embodiments, additional or different computing systemsor code modules may perform some or all of the functionalities describedherein. The methods and processes described herein are also not limitedto any particular sequence, and the blocks, steps, or states relatingthereto can be performed in other sequences that are appropriate, forexample, in serial, in parallel, or in some other manner. Tasks orevents may be added to or removed from the disclosed exampleembodiments. Moreover, the separation of various system components inthe implementations described herein is for illustrative purposes andshould not be understood as requiring such separation in allimplementations. It should be understood that the described programcomponents, methods, and systems can generally be integrated together ina single computer product or packaged into multiple computer products.Many implementation variations are possible.

The processes, methods, and systems may be implemented in a network (ordistributed) computing environment. Network environments includeenterprise-wide computer networks, intranets, local area networks (LAN),wide area networks (WAN), personal area networks (PAN), cloud computingnetworks, crowd-sourced computing networks, the Internet, and the WorldWide Web. The network may be a wired or a wireless network or any othertype of communication network.

The systems and methods of the disclosure each have several innovativeaspects, no single one of which is solely responsible or required forthe desirable attributes disclosed herein. The various features andprocesses described above may be used independently of one another, ormay be combined in various ways. All possible combinations andsub-combinations are intended to fall within the scope of thisdisclosure. Various modifications to the implementations described inthis disclosure may be readily apparent to those skilled in the art, andthe generic principles defined herein may be applied to otherimplementations without departing from the spirit or scope of thisdisclosure. Thus, the claims are not intended to be limited to theimplementations shown herein, but are to be accorded the widest scopeconsistent with this disclosure, the principles and the novel featuresdisclosed herein.

Certain features that are described in this specification in the contextof separate implementations also can be implemented in combination in asingle implementation. Conversely, various features that are describedin the context of a single implementation also can be implemented inmultiple implementations separately or in any suitable sub-combination.Moreover, although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asub-combination or variation of a sub-combination. No single feature orgroup of features is necessary or indispensable to each and everyembodiment.

Conditional language used herein, such as, among others, “can,” “could,”“might,” “may,” “e.g.,” and the like, unless specifically statedotherwise, or otherwise understood within the context as used, isgenerally intended to convey that certain embodiments include, whileother embodiments do not include, certain features, elements and/orsteps. Thus, such conditional language is not generally intended toimply that features, elements and/or steps are in any way required forone or more embodiments or that one or more embodiments necessarilyinclude logic for deciding, with or without author input or prompting,whether these features, elements and/or steps are included or are to beperformed in any particular embodiment. The terms “comprising,”“including,” “having,” and the like are synonymous and are usedinclusively, in an open-ended fashion, and do not exclude additionalelements, features, acts, operations, and so forth. Also, the term “or”is used in its inclusive sense (and not in its exclusive sense) so thatwhen used, for example, to connect a list of elements, the term “or”means one, some, or all of the elements in the list. In addition, thearticles “a,” “an,” and “the” as used in this application and theappended claims are to be construed to mean “one or more” or “at leastone” unless specified otherwise.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: A, B, or C” is intended to cover: A, B, C,A and B, A and C, B and C, and A, B, and C. Conjunctive language such asthe phrase “at least one of X, Y and Z,” unless specifically statedotherwise, is otherwise understood with the context as used in generalto convey that an item, term, etc. may be at least one of X, Y or Z.Thus, such conjunctive language is not generally intended to imply thatcertain embodiments require at least one of X, at least one of Y and atleast one of Z to each be present.

Similarly, while operations may be depicted in the drawings in aparticular order, it is to be recognized that such operations need notbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. Further, the drawings may schematically depict one more exampleprocesses in the form of a flowchart. However, other operations that arenot depicted can be incorporated in the example methods and processesthat are schematically illustrated. For example, one or more additionaloperations can be performed before, after, simultaneously, or betweenany of the illustrated operations. Additionally, the operations may berearranged or reordered in other implementations. In certaincircumstances, multitasking and parallel processing may be advantageous.Moreover, the separation of various system components in theimplementations described above should not be understood as requiringsuch separation in all implementations, and it should be understood thatthe described program components and systems can generally be integratedtogether in a single software product or packaged into multiple softwareproducts. Additionally, other implementations are within the scope ofthe following claims. In some cases, the actions recited in the claimscan be performed in a different order and still achieve desirableresults.

What is claimed is:
 1. A method comprising: creating, in a firstapplication which implements a first rigging control protocol, a riggingcontrol system description, the rigging control system description beingdefined according to a different second rigging control protocol, andthe rigging control system description specifying a rigging controlinput and at least one rule for operating on the rigging control inputto produce a rigging control output; writing the rigging control systemdescription to a data file; and initiating transfer of the data file toa second application.
 2. The method of claim 1, wherein the firstrigging control protocol comprises one or more data formats, datastructures, functions, or computational units that are specific to thefirst application.
 3. The method of claim 2, wherein the second riggingcontrol protocol comprises one or more data formats, data structures,functions, or computational units that are different than in the firstrigging control protocol.
 4. The method of claim 1, wherein the firstapplication is a digital content creation application whose primaryfunction comprises creation of virtual characters, and wherein thesecond application is a real-time engine.
 5. The method of claim 1,wherein the input specifies a characteristic of a lower-order riggingelement.
 6. The method of claim 5, wherein the lower-order riggingelement comprises a core skeleton for the virtual character.
 7. Themethod of claim 6, wherein the input comprises a transform for a jointin the core skeleton.
 8. The method of claim 1, wherein the outputspecifies a characteristic of a higher-order rigging element.
 9. Themethod of claim 8, wherein the higher-order rigging element comprises ahigher-order skeleton.
 10. The method of claim 9, wherein the outputcomprises a transform for a joint in the higher-order skeleton.
 11. Themethod of claim 8, wherein the higher-order rigging element comprises ablendshape.
 12. The method of claim 11, wherein the output comprises ablendshape weight.
 13. The method of claim 1, wherein the control systemdescription comprises a mathematical operation.
 14. The method of claim13, wherein the mathematical operation comprises a radial basisfunction.
 15. The method of claim 13, wherein the mathematical operationcomprises a Boolean operation.
 16. The method of claim 1, wherein themethod is performed by a framework embedded in the first application.17. The method of claim 16, wherein the framework is a plug-in for thefirst application.
 18. The method of claim 1, wherein the virtualcharacter comprises one or more rigging assets selected from the groupcomprising: a polygon mesh, a core skeletal system, a higher-orderskeletal system, a blendshape, and an animation.
 19. An apparatuscomprising: an authoring tool configured to create, in a firstapplication which implements a first rigging control protocol, a riggingcontrol system description, the rigging control system description beingdefined according to a different second rigging control protocol, andthe rigging control system description specifying a rigging controlinput and at least one rule for operating on the rigging control inputto produce a rigging control output; and a serialization tool configuredto write the rigging control system description to a data file, and toinitiate transfer of the data file to a second application.
 20. Anon-transitory computer-readable medium which, when read by a computingdevice, causes the computing device to perform a method comprising:creating, in a first application which implements a first riggingcontrol protocol, a rigging control system description, the riggingcontrol system description being defined according to a different secondrigging control protocol, and the rigging control system descriptionspecifying a rigging control input and at least one rule for operatingon the rigging control input to produce a rigging control output;writing the rigging control system description to a data file; andinitiating transfer of the data file to a second application.